EX-4.2



 Exhibit 4.2 
  






 
 Exhibit 4.2 NUMBER CPB

INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE 
C CAPNIA 
SHARES 
SEE REVERSE FOR CERTAIN DEFINITIONS AND LEGENDS 
This certifies that 
is the record holder of 
FULLY PAID AND NONASSESSABLE SERIES B CONVERTIBLE PREFERRED STOCK, $0.001 PAR VALUE, OF

CAPNIA, INC. 
transferable on the books of the corporation in person or by
duly authorized attorney upon surrender of this Certificate properly endorsed. This Certificate is not valid until countersigned by the Transfer Agent and registered by the Registrar. 
WITNESS the facsimile seal of the Corporation and the facsimile signatures of its duly authorized officers. 
Dated: 
CERTIFICATE OF STOCK 
PRESIDENT 
CAPNIA, INC. 
CORPORATE SEAL 
AUGUST 25, 1999 
DELAWARE 
SECRETARY 
COUNTERSIGNED AND REGISTERED: 
AMERICAN STOCK TRANSFER & TRUST COMPANY, LLC

(BROOKLYN, NY) 
TRANSFER AGENT AND REGISTRAR 
BY: 
AUTHORIZED SIGNATURE 
HERITAGE BANKNOTE 







 



 
 The Corporation shall furnish without charge to each stockholder who so requests a statement of the powers, designations, preferences
and relative, participating, optional or other special rights of each class of stock of the Corporation or series thereof and the qualifications, limitations or restrictions of such preferences and/or rights. Such requests shall be made to the
Corporation’s Secretary at the principal office of the Corporation. 
KEEP THIS CERTIFICATE IN A SAFE PLACE. IF IT IS LOST, STOLEN,OR DESTROYED THE CORPORATION
WILL REQUIRE A BOND INDEMNITY AS A CONDITION TO THE ISSUANCE OF A REPLACEMENT CERTIFICATE. 
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: 
TEN COM – as tenants in common

TEN ENT – as tenants by the entireties 
JT TEN – as joint tenants
with right of survivorship and not as tenants in common 
COM PROP – as community property 
UNIF GIFT MIN ACT – Custodian 
(Cust) (Minor) 
under Uniform Gifts to Minors 
Act (State) 
UNIF TRF MIN ACT – Custodian (until age) 
(Cust) (Minor) under Uniform Transfers

to Minors Act (State) 
Additional abbreviations may also be used though not in
the above list. 
FOR VALUE RECEIVED, hereby sell(s), assign(s) and transfer(s) unto 
PLEASE INSERT SOCIAL SECURITY OR OTHER 
IDENTIFYING NUMBER OF ASSIGNEE 
(PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING ZIP CODE, OF ASSIGNEE) 
shares

of the capital stock represented by within Certificate, and do hereby irrevocably constitute and appoint 
attorney-in-fact to transfer the said stock on the books of the within named Corporation with full power of the substitution in the premises. 
Dated 
Signature(s) Guaranteed: X X 
NOTICE: 
THE SIGNATURE TO THIS ASSIGNMENT MUST CORRESPOND WITH THE NAME AS WRITTEN UPON THE
FACE OF THE CERTIFICATE IN EVERY PARTICULAR, WITHOUT ALTERATION OR ENLARGEMENT OR ANY CHANGE WHATSOEVER. 
By 
THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION, (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED
SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-15. GUARANTEES BY A NOTARY PUBLIC ARE NOT ACCEPTABLE. SIGNATURE GUARANTEES MUST NOT BE DATED.