IPHIMEDIA, 
217 
A MPHIP ODA . PH OX IDES. 
KATATORIA. 
Genus— IPHIMEDIA. 
Iphimedia. Rathke, Beitr. zurFaun. Norwegens, Nov. Act. Leop. vol. xx, 
p. 89 (1843). Spence Bate, Ann. Nat. Hist. 2 ser. xix. 
p. 141, Feb. 1857. Cat. Crust. Amph. Brit. Mus. p. 123. 
White, Pop. Hist. Brit. Crust, p. 176 (not Iphimedia , Dana). 
Microcheles. Kroyer, Tidsk. Nat. sec. 2, vol. ii. p. 5. 
Generic character. Cephalon produced anteriorly. Pereion 
distended. Pleon compressed. Eyes two. Antennae simple. 
Third pair of siagonopoda not unguiculate. First pair of gna- 
thopoda feeble ; second also feeble, imperfectly subchelate. 
Pereiopoda robust, having large and powerful dactyla. Pos- 
terior pair of pleopoda biramous. Telson single, squamous, 
emarginate. 
In this genus the head is produced anteriorly. The 
body is dorsally rounded and laterally distended, while 
the tail is very rapidly narrowed. It is furnished with 
a small eye upon each side of the head. The antennae 
are subequal, and without a secondary appendage ; the 
organs attendant upon the mouth are considerably pro- 
jected forwards. The first pair of legs are feeble, and 
have the fingers rudimentary ; the second are likewise 
feeble, but terminate in an imperfectly chelate organ. 
The coxae increase in depth to the fourth, which is 
produced inferiorly to a sharp point. The last three 
pairs of legs are tolerably strong, and terminate in 
powerful fingers. The last pair of caudal appendages 
are double-branched, and the telson is single, squami- 
form, and emarginate. 
Our description differs from that of Rathke in a 
