NOLO R: 
Tue present number of the Memoirs is the first of a series of ‘Selections from Em- 
bryological Monographs,” which it is proposed to issue as Vol. [X. of the Memoirs of the 
Museum, so as to give to the student in an easily accessible form a more or less com- 
plete iconography of the embryology of each important group of the animal kingdom. 
This selection is not intended to be a hand-book, but rather an atlas to accompany any 
general work on the subject. The plates will be issued in parts, as fast as practicable, 
each part covering a somewhat limited field, and occasional appendices may be published 
to prevent the plates from becoming antiquated. 
The quarto illustrations will be accompanied by a carefully prepared explanation, 
and by a bibliography, in octavo, to be made as complete as possible. The Bibliography 
(by Walter Faxon) which accompanies this number (Crustacea) has been published 
as No. 6 of Vol. TX. of the Bulletin of the Museum. 
The parts devoted to Echinoderms, Acalephs, and Polyps are well advanced. 
The phenomena connected with the fecundation and maturation of the egg, and the 
history of the formation of the embryonic layers, will be treated in a separate part, 
without regard to the systematic zodlogical connection of the observations. 
A number of original drawings will be incorporated with these selections wherever 
they supplement published material. 
The work was planned as early as 1873. I hoped then to publish it with the col- 
laboration of Dr. A. S. Packard, Jr. Other duties prevented this plan from being 
carried out. In 1875, Professor John McCrady kindly consented to become my col- 
laborator, but his removal from Cambridge stopped the undertaking in its earliest 
stages. 
ALEXANDER AGASSIZ. 
MvseuM oF CoMPARATIVE Zo6LoGy, 
Cambridge, Mass., U.S. A. 
JULY, 1882. 
