LETTER OF TRANSMITTAL. 



CAMBRIDGE, MASS., 



. May 25, 1880. 



SIR: I have the honor to transmit herewith for approval 

 and for publication the " History of North American Pinnipeds," 

 being a monograph of the Walruses, Sea-Lions, Sea-Bears, and 

 Seals of North America. 



Very respectfully, your obedient servant, 



J. A. ALLEN. 

 F. V. HAYDF,N, 



Washington, D. C. 



