Exhibit 4.1

NUMBER SHARES
REV rEVO Biologics, Inc.
INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE
SEE REVERSE FOR CERTAIN DEFINITIONS
CUSIP 76155H 10 5
THIS CERTIFIES THAT
SPECIMEN
IS THE OWNER OF
FULLY PAID AND NON-ASSESSABLE SHARES OF THE COMMON STOCK, $0.01 PAR VALUE PER SHARE, OF
rEVO Biologics, Inc.
transferable on the books of the Corporation in person or by duly authorized attorney upon surrender of the Certificate properly endorsed. This Certificate is not valid until countersigned by the Transfer Agent and registered by the Registrar.
Witness the facsimile signatures of the Corporation’s duly authorized officers.
Dated:
SENIOR VICE PRESIDENT, CHIEF FINANCIAL OFFICER, SECRETARY AND TREASURER
PRESIDENT, CHIEF EXECUTIVE OFFICER AND DIRECTOR
COUNTERSIGNED AND REGISTERED:
AMERICAN STOCK TRANSFER & TRUST COMPANY, LLC
(Brooklyn, NY)
Transfer Agent and Registrar
By Authorized Officer
AMERICAN BANK NOTE COMPANY

The following abbreviations, when used in the inscription on the face of this Certificate, shall be construed as though they were written out in full according to applicable laws or regulations:

Additional abbreviations may also be used though not in the above list.

For value received,                      hereby sells, assigns and transfers unto

(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE)

_____________________________________________________________________________________________________  shares represented by the within Certificate, and does hereby irrevocably constitute and appoint

_________________________________________________________________________________________________, attorney to transfer the said shares on the books of the within named Corporation with full power of substitution in the premises.