IPHIMEDTA OBESA. 
219 
A MPHIP ODA . PH OXIDES. 
NATATORIA . 
IPHIMEDIA OBESA. 
Specific character. Ceplialon anteriorly produced, but not- much depressed. 
Last segment of the pereion, and three first of the pleon, furnished on each 
side of the dorsal central line with a posteriorly-directed tooth. 
Length 2 8 g inch. 
Ipldmedia obesa. Bathke, Beitr. zur Faun. Norwegens, Nov. Act. Leop. 
vol. xx. (1843), p. 89, pi. iii. fig. 1. Spence Bate, 
Ann. Nat. 2 ser. xix. p. 141, Feb. 1857. Cat. 
Amph. Crust. Brit. Mus. p. 123, pi. xxii. fig. 2. 
White, Pop. Hist. Brit. Crust, p. 176, pi. x. fig. 6. 
Microcheles armata. Kroyer, Nat. Tidskr. sec. 2, vol. ii. p. 5. 
The head, which is anteriorly produced, has the long 
projection not curved downwards. The last segment of 
the body and the first three of the tail are severally 
furnished with two dorsal teeth, one being on each side 
of the central line ; the posterior margin of the third 
segment of the tail has likewise a strong tooth near the 
centre, and another at the infero-posterior angle. The 
eyes are somewhat reniform, and red in colour. The 
antennae are subequal, and about one-fourth of the 
length of the animal. The first pair of legs are weak, 
and have the hand long, with the infero-distal extremiy 
