CYRTOPHIUM. 
479 
AMP II IPOD A. 
NATATORTA, 
P OD 0 CERIDES. 
Genus— CYRTOPHIUM. 
Cyrtophium. Dana, U. S. Explor. Exped. p. 839. Spence Bate, Ann. 
Nat. Hist. 2 ser. xix. p. 145. Cat. Ampli. Brit. Mus. 
p. 278. White, Pop. Hist. Brit. Crust, p. 195. 
Platophium. Dana, U. S. Explor. Exped. p. 888. 
Lcetmatophylus. Bruzelius, Skand Ampli. Gramm, p. 11, pi. i. fig. 1. 
Generic character. Cephalon subquadrate. Pereion dis- 
tended. Pleon narrow. Eyes prominent. Antennae subpedi- 
form ; inferior pair the longer. Gnathopoda subchelate ; second 
pair much larger than the first pair. Posterior pair of pleopoda 
rudimentary. Telson squamiform. 
In this genus the animals, when viewed from above, 
have the head very square, the body distended to an 
oval, while the tail is considerably narrowed, and 
generally lies inflected against the under side of the 
body. The eyes are prominent. The antennae are 
subpediform, the flagella not being multi-articulate ; 
and the inferior pair always longer than the superior. 
The first two pairs of legs have the hands subchelate, 
the second pair being considerably larger than the first. 
The last two pairs of walking legs are considerably 
longer than the others. The caudal appendages are 
successively shorter posteriorly, the last pair being quite 
rudimentary, and scarcely longer than the central ter- 
minal scale. 
It will be perceived that we have united Dana’s two 
genera into one, since the only distinction that the 
author admits between Platophium and Cyrtophium de- 
pends upon “ the respective lengths of the branches 
belonging to the caudal appendages, the more lamellar 
