42 REVIEWS. 
the eared seals, have the ‘‘ sagittal groove,” etc., as above de- 
scribed, as do also the males till they have attained nearly their 
full size. The sagittal crest in the males of Eumetopias and 
Callorhinus rises at first as a double ridge on each side of the 
sagittal suture, beginning at the hinder part of thé skull. It 
develops most rapidly in its posterior part, and gradually ex- 
- tends anteriorly to a point opposite the orbital processes. Grad- 
ually the laminæ of this double plate become soldered into one, 
uniting first posteriorly, while anteriorly the crest remains com- 
posed of two closely applied thin plates, which, in old age, be- 
come firmly united the whole length. The sagittal crest in old 
male skulls of Zalophus hence differs from the corresponding crest 
in Eumetopias and Callorhinus, only in being relatively somewhat 
higher, and in being more produced anteriorly. I am not sure, 
however, .that in very aged animals even this slight difference 
would be constant. In one of the skulls of Zalophus I have seen, 
the two plates were not entirely soldered at their anterior end, 
thus indicating their development primarily as a double plate, as 
in Eumetopias and Callorhinus. The only other character given 
48 separating these two groups—that of the rostral profile —I 
deem too trivial to require more than the incidental remark already 
given to it. 
In concluding, I may add that the deservedly high standing of 
my critic as a naturalist seemed to demand from me, in justice to 
myself, some notice of his sweeping criticisms, especially since 
not merely the assumed value of the characters given by me as 
distinguishing what I considered to be two primary groups of the 
Otariadæ were questioned, but also even the existence of such 
distinctions ; but more especially it was due to the interests of sci- 
ence that his incorrect diagnosis of one of the two groups he con- 
siders as the two primary groups of this family, should not pass 
unnoticed, since on this error was based a new classification of the 
Otariade. Having done this, the writer will here let the subject 
rest.— J. A. A. 
Tue EARLY STAGES OF ICHNEUMON Parasrres.*-—These em- 
bryological studies were made by Prof. Ganin on the eggs of 
Platygaster, Polynema, Teleas and Ophioneurus, which are minute 
, w. Diebold and Kölliker: : 2 i 
plates. Leipzig. ` ws Zeitschrift. 1869, pp. 381-451, with 4 . 
