132 THE ATLANTIC. [CHaP, Il. 
elongated tube with three openings; the stomach, a large sac 
with a small intestine leading from its base to the excretory 
opening in the telson: in the female two large rose-colored 
ovaries, the oviducts passing to an opening covered by two 
small iamellee, at the base of the first segment of the pereion ; 
in the male two elongated testes, their ducts opening between 
the appendages of the seventh segment. 
The head is large and greatly inflated, and its upper surface 
is entirely occupied by two enormous faceted eyes, reminding 
one of the eyes of glina among trilobites. There are two 
rows of spines along the lateral borders of the head, and some 
spines are placed round the mouth, which is in the usual posi- 
tion at the base of the cephalic segment on the lower surface 
of the body. The first pair of antenne only are developed in 
either sex. The antenna consists of two joints, and is attached 
to the anterior margin of the head. 
The parts of the mouth and the maxillipeds are very small; 
the two gnathopods are terminated by claws, as in the Typhids, 
and act functionally as second and third maxillipeds. 
The pereion consists of seven segments; and the pleon of 
five, to the two last of which the caudal appendages are at- 
tached. The five pairs of ambulatory legs are long and slen- 
der, and the three pairs of “swimmerets” are normal. The 
eggs are large and few in number: some of those observed 
contained embryos in which nearly all the appendages were 
developed, showing that the young undergo no metamorphosis. 
Dr. von Willemoes-Suhm, who has carefully described this 
singular form, has proposed to establish for the genus a fam- 
ily Cysrosomip#, holding a place intermediate between the 
Typuip# and the Puronomip”&. 
Two small specimens of Centrostephanus longispinus were 
entangled in the trawl-net, and many star-fishes, including Ar- 
chaster Andromeda and bifrons, Astrogonium longimanum, and, 
among other Ophiurids, some fine examples of Ophiomusiwm 
