\N> 



Ulusntm of Compitnittbe soologij, 



Cambridge, Mass., October, 1876. 



Owing to a mistake of the printer, Mr. Allen's Memoir was not struck 



off on paper uniform with that of the former publications of the Museum. 



This was not discovered until the whole edition had been printed, too 



late to rectify the blunder. 



ALEXANDER AGASSIZ. 



