<PAGE>
 
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 18, 1998, 
=======================================================================
                                                REGISTRATION NO. 333-________
                                                ================================


                                 _____________

                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C.  20549
                                  ___________

                                   FORM S-8
            REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                       NATURAL MICROSYSTEMS CORPORATION
            (Exact name of registrant as specified in its charter)
                                  ___________

           DELAWARE                                         04-2814586
(State or other jurisdiction of                  (I.R.S. Employer Identification
 incorporation or organization)                                 No.)
                                               

                             100 CROSSING BOULEVARD
                      FRAMINGHAM, MASSACHUSETTS 01702-5406
                                 (508) 620-9300
  (Address, including zip code, and telephone number, including area code, of
                   registrant's principal executive offices)
                                  ___________

                             1993 STOCK OPTION PLAN
                       1993 EMPLOYEE STOCK PURCHASE PLAN
                      1995 NON-STATUTORY STOCK OPTION PLAN
                             (Full title of plans)
                                  ___________

                              ROBERT P. SCHECHTER
                     PRESIDENT AND CHIEF EXECUTIVE OFFICER
                        NATURAL MICROSYSTEMS CORPORATION
                             100 CROSSING BOULEVARD
                     FRAMINGHAM, MASSACHUSETTS  01702-5406
                    (Name and address of agent for service)

<TABLE>
<CAPTION>
======================================================================================================== 
                                  CALCULATION OF REGISTRATION FEE
-------------------------------------------------------------------------------------------------------- 
                                               Proposed             Proposed
 Title of securities     Amount to be     maximum offering          maximum                Amount of
  to be registered      registered (1)    price per share (2)       aggregate           registration fee
---------------------   --------------    -------------------    offering price (2)     ----------------
                                                                 ------------------
-------------------------------------------------------------------------------------------------------- 
<S>                    <C>               <C>                   <C>                 <C>
Common Stock,
 $.01 par value        1,040,000 shares       $16.125               $16,770,000            $4,947.15
========================================================================================================
</TABLE>

(1) Plus such additional number of shares as may be required pursuant to the
Plan in the event of a stock dividend, split-up of shares, recapitalization or
other similar change in the Common Stock.

(2) Estimated solely for the purpose of calculating the registration fee, in
accordance with Rule 457(h)(1), on the basis of the average of the high and low
prices of the Common Stock as reported on the Nasdaq National Market on June 15,
1998.
<PAGE>
 
                                 EXPLANATORY NOTE

     This Registration Statement has been prepared in accordance with the
requirements of Form S-8, as amended.  The purpose of this Registration
Statement is to register 1,040,000 shares of Common Stock, $.01 par value, of
Natural MicroSystems Corporation (the "Company"); 400,000 of which shares have
been reserved for issuance under the Company's 1995 Non-Statutory Stock Option
Plan, 440,000 of which shares have been reserved for issuance under the
Company's 1993 Stock Option Plan and 200,000 of which shares have been reserved
for issuance under the Company's 1993 Employee Stock Purchase Plan.  After
giving effect to a 2-for-1 stock split effective November 21, 1996, 380,000
shares issuable under the 1993 Stock Option Plan and 100,000 shares issuable
under the Employee Stock Purchase Plan have previously been registered pursuant
to Registration Statement No. 33-76324, and 400,000 shares issuable under the
1995 Non-Statutory Stock Option Plan, 1,080,000 shares issuable under the 1993
Stock Option Plan and 100,000 shares issuable under the 1993 Employee Stock
Purchase Plan have been previously registered pursuant to Registration Statement
No. 333-09135.
<PAGE>
 
                                    PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.   Incorporation of Documents by Reference
          ---------------------------------------

     The following documents are hereby incorporated by reference in this
Registration Statement:

          (a) The Company's Form 10-K for the year ended December 31, 1997 filed
     with the Securities and Exchange Commission (the "Commission") under the
     Securities Exchange Act of 1934, as amended (the "Exchange Act"); and

          (b) The Company's Form 10-Q for the quarter ended March 31, 1997 filed
     with the Securities and Exchange Commission (the "Commission") under the
     Exchange Act; and

          (c) The description of the Company's Common Stock incorporated by
     reference in the Company's registration statement on Form 8-A (SEC File No.
     0-23282) filed with the Commission on January 25, 1994 from the
     registration statement on Form S-1 (SEC File No. 33-72596) filed with the
     Commission on December 6, 1993.

In addition, all documents filed by the Company after the initial filing date of
this registration statement pursuant to Sections 13(a), 13(c), 14 and 15(d) of
the Exchange Act, and prior to the filing of a post-effective amendment which
indicates that all shares registered hereunder have been sold or which de-
registers all shares then remaining unsold, shall be deemed to be incorporated
by reference in this registration statement and to be a part hereof from the
date of filing of such documents.

Item 4.   Description of Securities
          -------------------------

     Not applicable.

Item 5.   Interests of Named Experts and Counsel
          --------------------------------------
 
     The legality of the shares of Common Stock offered hereby has been passed
upon for the Company by Choate, Hall & Stewart, (a partnership including
professional corporations), 53 State Street, Exchange Place, Boston,
Massachusetts 02109. Richard N. Hoehn, a partner of the firm, is Assistant
Secretary of the Company.

                                      II-1
<PAGE>
 
Item 6.   Indemnification of Officers and Directors
          -----------------------------------------

     Section 145 of the General Corporation Law of the State of Delaware
provides that a corporation may indemnify a director, officer, employee or agent
against expenses (including attorneys' fees), judgments, fines and for amounts
paid in settlement in respect of or in successful defense of any action, suit or
proceeding if he acted in good faith and in a manner he reasonably believed to
be in or not opposed to the best interests of the corporation, and, with respect
to any criminal action or proceeding, had no reasonable cause to believe his
conduct was unlawful.
 
     Article Tenth of the Company's Fourth Restated Certificate of Incorporation
provides that no director of the Company shall be personally liable to the
Company or its stockholders for monetary damages for breach of fiduciary duty as
a director, except for liability (i) for any breach of the director's duty of
loyalty, (ii) for acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the Delaware General Corporation Law or (iv) for any transaction from which the
director derived an improper personal benefit. Article Tenth further provides
that a director's personal liability shall be eliminated or limited in the
future to the fullest extent permitted from time to time by the Delaware General
Corporation Law.

     Article Eleventh of the Company's Fourth Restated Certificate of
Incorporation provides that the Company shall, to the fullest extent permitted
from time to time under the Delaware General Corporation Law, indemnify each of
its directors and officers against all expenses (including attorneys' fees),
judgments, fines and amounts paid in settlement in respect of any action, suit
or proceeding in which such director or officer may be involved or with which he
may be threatened, while in office or thereafter, by reason of his or her
actions or omissions in connection with services to the Company, such
indemnification to include prompt payment of expenses in advance of the final
disposition of any such action, suit or proceeding.


Item 7.   Exemption from Registration Claimed.
          ----------------------------------- 

     Not applicable.

Item 8.   Exhibits
          --------

     5.1  Opinion of Choate, Hall & Stewart as to the legality of the shares
          being registered.

     10.1 The Company's 1993 Stock Option Plan  (As Amended and Restated
          Effective March 4, 1998).

                                      II-2
<PAGE>
 
     10.2 Registrant's 1993 Employee Stock Purchase Plan (As Amended and
          Restated Effective March 4, 1998).

     10.3 Registrant's 1995 Non-Statutory Stock Option Plan (As Amended and
          Restated December 19, 1996).

     23.1 Consent of Coopers & Lybrand L.L.P.

     23.2 Consent of KPMG Peat Marwick LLP

     23.3 Consent of Choate, Hall & Stewart (included in
          Exhibit 5.1).

     24.1 Power of Attorney (included in page II-5).

Item 9.   Undertakings
          ------------

     (a)  The Company hereby undertakes:

          (1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement to include any
material information with respect to the plan of distribution not previously
disclosed in the registration statement or any material change to such
information in the registration statement;

          (2) that, for the purpose of determining any liability under the
Securities Act of 1933, as amended (the "Securities Act"), each such post-
effective amendment shall be deemed to be a new registration statement relating
to the securities offered therein, and the offering of such securities at that
time shall be deemed to be the initial bona fide offering thereof; and

          (3) to remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering.

     (b) The Company hereby undertakes that, for purposes of determining any
liability under the Securities Act, each filing of the Company's annual report
pursuant to Section 13(a) or Section 15(d) of the Exchange Act that is
incorporated by reference in the registration statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     (h) Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers and controlling persons of the
Company 

                                      II-3
<PAGE>
 
pursuant to the foregoing provisions, or otherwise, the Company has been advised
that in the opinion of the Commission such indemnification is against public
policy as expressed in the Securities Act and is, therefore, unenforceable. In
the event that a claim for indemnification against such liabilities (other than
the payment by the Company of expenses incurred or paid by a director, officer
or controlling person of the Company in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the Company will, unless in
the opinion of counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.

                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the Company
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing a Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the Town of Framingham, Commonwealth of Massachusetts on June 12,
1998.


                              Natural MicroSystems Corporation
                              (Issuer and Employer)

                              By:   /s/ Robert P. Schechter
                                    -----------------------------------------
                                    Robert P. Schechter, President
                                    and Chief Executive Officer
 

                                      II-4
<PAGE>
 
                               POWER OF ATTORNEY

     KNOW ALL MEN BY THESE PRESENTS, that each individual whose signature
appears below constitutes and appoints Robert P. Schechter, John F. Kennedy and
Richard N. Hoehn, jointly and severally, his true and lawful attorneys-in-fact
and agents with full powers of substitution, for him and in his name, place and
stead, in any and all capacities, to sign any and all amendments (including
post-effective amendments) to this registration statement, and to file the same,
with all exhibits thereto, and all documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorneys-in-fact and
agents, and each of them, full power and authority to do and perform each and
every act and thing requisite and necessary to be in and about the premises, as
fully to all intents and purposes as he might or could do in person, hereby
ratifying and confirming all that said attorneys-in-fact and agents, or any of
them, or their or his substitute or substitutes, may lawfully do or cause to be
done by virtue thereof.

     Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed below on the dates indicated by the
following persons in the capacities indicated.
<TABLE>
<CAPTION>
 
Name                                             Capacity                              Date
----                                             --------                              ----
<S>                            <C>                             <C>
 
/s/ Robert P. Schechter                  President, Chief Executive                 6/12/98
Robert P. Schechter                      Officer and Director                       
                                         (Principal Executive Officer)              
                                                                                    
/s/ John F. Kennedy                      Chief Financial Officer                    6/12/98
John F. Kennedy                          (Principal Financial Officer)              
                                                                                    
/s/ David C. Flynn                       Controller                                 6/12/98
David C. Flynn                           (Principal Accounting Officer)             
                                                                                    
/s/ Charles T. Foskett                   Director                                   6/12/98
Charles T. Foskett                       
                                                                                    
/s/ Ronald W. White                      Director                                   6/3/98
Ronald W. White                                                                     
                                                                                    
/s/ Zenas W. Hutcheson, III              Director                                   6/12/98
Zenas W. Hutcheson, III                                                             
                                                                                    
/s/ W. Frank King                        Director                                   6/12/98
W. Frank King                            
                                                                                    
/s/ Pamela D. A. Reeve                   Director                                   6/12/98
Pamela D. A. Reeve
</TABLE>

                                      II-5
<PAGE>
 
                               INDEX TO EXHIBITS
                               -----------------

Exhibit Number                                                       Page No.
--------------                                                       ------- 

     5.1    Opinion of Choate, Hall & Stewart as to the legality
            of the shares being registered.

     10.1   The Company's 1993 Stock Option Plan  (As Amended and 
            Restated Effective March 4, 1998).

     10.2   Registrant's 1993 Employee Stock Purchase Plan (As 
            Amended and Restated Effective March 4, 1998).

     10.3   Registrant's 1995 Non-Statutory Stock Option Plan (As 
            Amended and Restated December 19, 1996).

     23.1   Consent of Coopers & Lybrand L.L.P.

     23.2   Consent of KPMG Peat Marwick LLP

     23.3   Consent of Choate, Hall & Stewart (included in 
            Exhibit 5.1).

     24.1   Power of Attorney (included in page II-5).

                                      II-6
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 18223}]
{"company-data": {"conformed-name": "NATURAL MICROSYSTEMS CORP", "cik": "0000915866", "assigned-sic": "3661", "irs-number": "042814586", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-57141", "film-number": "98650296"}, "business-address": {"street1": "100 CROSSING BLVD", "city": "FRAMINGHAM", "state": "MA", "zip": "01702", "phone": "5086501300"}, "mail-address": {"street1": "8 ERIE DR", "city": "NATICK", "state": "MA", "zip": "01760"}}
AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JUNE 18, 1998, 
=======================================================================
                                                REGISTRATION NO. 333-________
                                                ================================

                                 _____________

                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C.  20549
                                  ___________

                                   FORM S-8
            REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                       NATURAL MICROSYSTEMS CORPORATION
            (Exact name of registrant as specified in its charter)
                                  ___________

           DELAWARE                                         04-2814586
(State or other jurisdiction of                  (I.R.S. Employer Identification
 incorporation or organization)                                 No.)
                                               

                             100 CROSSING BOULEVARD
                      FRAMINGHAM, MASSACHUSETTS 01702-5406
                                 (508) 620-9300
  (Address, including zip code, and telephone number, including area code, of
                   registrant's principal executive offices)
                                  ___________

                             1993 STOCK OPTION PLAN
                       1993 EMPLOYEE STOCK PURCHASE PLAN
                      1995 NON-STATUTORY STOCK OPTION PLAN
                             (Full title of plans)
                                  ___________

                              ROBERT P. SCHECHTER
                     PRESIDENT AND CHIEF EXECUTIVE OFFICER
                        NATURAL MICROSYSTEMS CORPORATION
                             100 CROSSING BOULEVARD
                     FRAMINGHAM, MASSACHUSETTS  01702-5406
                    (Name and address of agent for service)
======================================================================================================== 
                                  CALCULATION OF REGISTRATION FEE
-------------------------------------------------------------------------------------------------------- 
                                               Proposed             Proposed
 Title of securities     Amount to be     maximum offering          maximum                Amount of
  to be registered      registered (1)    price per share (2)       aggregate           registration fee
---------------------   --------------    -------------------    offering price (2)     ----------------
                                                                 ------------------
--------------------------------------------------------------------------------------------------------
Common Stock,
 $.01 par value        1,040,000 shares       $16.125               $16,770,000            $4,947.15
========================================================================================================
(1) Plus such additional number of shares as may be required pursuant to the
Plan in the event of a stock dividend, split-up of shares, recapitalization or
other similar change in the Common Stock.

(2) Estimated solely for the purpose of calculating the registration fee, in
accordance with Rule 457(h)(1), on the basis of the average of the high and low
prices of the Common Stock as reported on the Nasdaq National Market on June 15,
1998.
EXPLANATORY NOTE

     This Registration Statement has been prepared in accordance with the
requirements of Form S-8, as amended.  The purpose of this Registration
Statement is to register 1,040,000 shares of Common Stock, $.01 par value, of
Natural MicroSystems Corporation (the "Company"); 400,000 of which shares have
been reserved for issuance under the Company's 1995 Non-Statutory Stock Option
Plan, 440,000 of which shares have been reserved for issuance under the
Company's 1993 Stock Option Plan and 200,000 of which shares have been reserved
for issuance under the Company's 1993 Employee Stock Purchase Plan.  After
giving effect to a 2-for-1 stock split effective November 21, 1996, 380,000
shares issuable under the 1993 Stock Option Plan and 100,000 shares issuable
under the Employee Stock Purchase Plan have previously been registered pursuant
to Registration Statement No. 33-76324, and 400,000 shares issuable under the
1995 Non-Statutory Stock Option Plan, 1,080,000 shares issuable under the 1993
Stock Option Plan and 100,000 shares issuable under the 1993 Employee Stock
Purchase Plan have been previously registered pursuant to Registration Statement
No. 333-09135.
PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.   Incorporation of Documents by Reference
          ---------------------------------------

     The following documents are hereby incorporated by reference in this
Registration Statement:

          (a) The Company's Form 10-K for the year ended December 31, 1997 filed
     with the Securities and Exchange Commission (the "Commission") under the
     Securities Exchange Act of 1934, as amended (the "Exchange Act"); and

          (b) The Company's Form 10-Q for the quarter ended March 31, 1997 filed
     with the Securities and Exchange Commission (the "Commission") under the
     Exchange Act; and

          (c) The description of the Company's Common Stock incorporated by
     reference in the Company's registration statement on Form 8-A (SEC File No.
     0-23282) filed with the Commission on January 25, 1994 from the
     registration statement on Form S-1 (SEC File No. 33-72596) filed with the
     Commission on December 6, 1993.

In addition, all documents filed by the Company after the initial filing date of
this registration statement pursuant to Sections 13(a), 13(c), 14 and 15(d) of
the Exchange Act, and prior to the filing of a post-effective amendment which
indicates that all shares registered hereunder have been sold or which de-
registers all shares then remaining unsold, shall be deemed to be incorporated
by reference in this registration statement and to be a part hereof from the
date of filing of such documents.

Item 4.   Description of Securities
          -------------------------

     Not applicable.

Item 5.   Interests of Named Experts and Counsel
          --------------------------------------
 
     The legality of the shares of Common Stock offered hereby has been passed
upon for the Company by Choate, Hall & Stewart, (a partnership including
professional corporations), 53 State Street, Exchange Place, Boston,
Massachusetts 02109. Richard N. Hoehn, a partner of the firm, is Assistant
Secretary of the Company.

                                      II-1
Item 6.   Indemnification of Officers and Directors
          -----------------------------------------

     Section 145 of the General Corporation Law of the State of Delaware
provides that a corporation may indemnify a director, officer, employee or agent
against expenses (including attorneys' fees), judgments, fines and for amounts
paid in settlement in respect of or in successful defense of any action, suit or
proceeding if he acted in good faith and in a manner he reasonably believed to
be in or not opposed to the best interests of the corporation, and, with respect
to any criminal action or proceeding, had no reasonable cause to believe his
conduct was unlawful.
 
     Article Tenth of the Company's Fourth Restated Certificate of Incorporation
provides that no director of the Company shall be personally liable to the
Company or its stockholders for monetary damages for breach of fiduciary duty as
a director, except for liability (i) for any breach of the director's duty of
loyalty, (ii) for acts or omissions not in good faith or which involve
intentional misconduct or a knowing violation of law, (iii) under Section 174 of
the Delaware General Corporation Law or (iv) for any transaction from which the
director derived an improper personal benefit. Article Tenth further provides
that a director's personal liability shall be eliminated or limited in the
future to the fullest extent permitted from time to time by the Delaware General
Corporation Law.

     Article Eleventh of the Company's Fourth Restated Certificate of
Incorporation provides that the Company shall, to the fullest extent permitted
from time to time under the Delaware General Corporation Law, indemnify each of
its directors and officers against all expenses (including attorneys' fees),
judgments, fines and amounts paid in settlement in respect of any action, suit
or proceeding in which such director or officer may be involved or with which he
may be threatened, while in office or thereafter, by reason of his or her
actions or omissions in connection with services to the Company, such
indemnification to include prompt payment of expenses in advance of the final
disposition of any such action, suit or proceeding.

Item 7.   Exemption from Registration Claimed.
          ----------------------------------- 

     Not applicable.

Item 8.   Exhibits
          --------

     5.1  Opinion of Choate, Hall & Stewart as to the legality of the shares
          being registered.

     10.1 The Company's 1993 Stock Option Plan  (As Amended and Restated
          Effective March 4, 1998).

                                      II-2
10.2 Registrant's 1993 Employee Stock Purchase Plan (As Amended and
          Restated Effective March 4, 1998).

     10.3 Registrant's 1995 Non-Statutory Stock Option Plan (As Amended and
          Restated December 19, 1996).

     23.1 Consent of Coopers & Lybrand L.L.P.

     23.2 Consent of KPMG Peat Marwick LLP

     23.3 Consent of Choate, Hall & Stewart (included in
          Exhibit 5.1).

     24.1 Power of Attorney (included in page II-5).

Item 9.   Undertakings
          ------------

     (a)  The Company hereby undertakes:

          (1) To file, during any period in which offers or sales are being
made, a post-effective amendment to this registration statement to include any
material information with respect to the plan of distribution not previously
disclosed in the registration statement or any material change to such
information in the registration statement;

          (2) that, for the purpose of determining any liability under the
Securities Act of 1933, as amended (the "Securities Act"), each such post-
effective amendment shall be deemed to be a new registration statement relating
to the securities offered therein, and the offering of such securities at that
time shall be deemed to be the initial bona fide offering thereof; and

          (3) to remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering.

     (b) The Company hereby undertakes that, for purposes of determining any
liability under the Securities Act, each filing of the Company's annual report
pursuant to Section 13(a) or Section 15(d) of the Exchange Act that is
incorporated by reference in the registration statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

     (h) Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers and controlling persons of the
Company 

                                      II-3
pursuant to the foregoing provisions, or otherwise, the Company has been advised
that in the opinion of the Commission such indemnification is against public
policy as expressed in the Securities Act and is, therefore, unenforceable. In
the event that a claim for indemnification against such liabilities (other than
the payment by the Company of expenses incurred or paid by a director, officer
or controlling person of the Company in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the Company will, unless in
the opinion of counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question whether such
indemnification by it is against public policy as expressed in the Securities
Act and will be governed by the final adjudication of such issue.

                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the Company
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing a Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the Town of Framingham, Commonwealth of Massachusetts on June 12,
1998.

                              Natural MicroSystems Corporation
                              (Issuer and Employer)

                              By:   /s/ Robert P. Schechter
                                    -----------------------------------------
                                    Robert P. Schechter, President
                                    and Chief Executive Officer
 

                                      II-4
POWER OF ATTORNEY

     KNOW ALL MEN BY THESE PRESENTS, that each individual whose signature
appears below constitutes and appoints Robert P. Schechter, John F. Kennedy and
Richard N. Hoehn, jointly and severally, his true and lawful attorneys-in-fact
and agents with full powers of substitution, for him and in his name, place and
stead, in any and all capacities, to sign any and all amendments (including
post-effective amendments) to this registration statement, and to file the same,
with all exhibits thereto, and all documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorneys-in-fact and
agents, and each of them, full power and authority to do and perform each and
every act and thing requisite and necessary to be in and about the premises, as
fully to all intents and purposes as he might or could do in person, hereby
ratifying and confirming all that said attorneys-in-fact and agents, or any of
them, or their or his substitute or substitutes, may lawfully do or cause to be
done by virtue thereof.

     Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed below on the dates indicated by the
following persons in the capacities indicated.
Name                                             Capacity                              Date
----                                             --------                              ----
/s/ Robert P. Schechter                  President, Chief Executive                 6/12/98
Robert P. Schechter                      Officer and Director                       
                                         (Principal Executive Officer)              
                                                                                    
/s/ John F. Kennedy                      Chief Financial Officer                    6/12/98
John F. Kennedy                          (Principal Financial Officer)              
                                                                                    
/s/ David C. Flynn                       Controller                                 6/12/98
David C. Flynn                           (Principal Accounting Officer)             
                                                                                    
/s/ Charles T. Foskett                   Director                                   6/12/98
Charles T. Foskett                       
                                                                                    
/s/ Ronald W. White                      Director                                   6/3/98
Ronald W. White                                                                     
                                                                                    
/s/ Zenas W. Hutcheson, III              Director                                   6/12/98
Zenas W. Hutcheson, III                                                             
                                                                                    
/s/ W. Frank King                        Director                                   6/12/98
W. Frank King                            
                                                                                    
/s/ Pamela D. A. Reeve                   Director                                   6/12/98
Pamela D. A. Reeve
II-5
INDEX TO EXHIBITS
                               -----------------

Exhibit Number                                                       Page No.
--------------                                                       ------- 

     5.1    Opinion of Choate, Hall & Stewart as to the legality
            of the shares being registered.

     10.1   The Company's 1993 Stock Option Plan  (As Amended and 
            Restated Effective March 4, 1998).

     10.2   Registrant's 1993 Employee Stock Purchase Plan (As 
            Amended and Restated Effective March 4, 1998).

     10.3   Registrant's 1995 Non-Statutory Stock Option Plan (As 
            Amended and Restated December 19, 1996).

     23.1   Consent of Coopers & Lybrand L.L.P.

     23.2   Consent of KPMG Peat Marwick LLP

     23.3   Consent of Choate, Hall & Stewart (included in 
            Exhibit 5.1).

     24.1   Power of Attorney (included in page II-5).

                                      II-6