CRUSTACEA. 



MuERA anisochir, Kroyer. 



Plate 66, fig. 8 a, animal, enlarged; 5, hand of second pair; c, leg 

 of first pair in female ; d, leg of second pair, ibid. ; d', same, of size to 

 correspond with 8 a. 



This species, from Eio Janeiro, is very near the setipes, but differs 

 in having the setae or hairs of the legs longer and more slender, and 

 the third joint of the six posterior legs not serrated behind for the 

 setae ; the superior antenna* are rather shorter than the body. Length 

 nearly six lines. Some of the hairs of the six posterior legs are longer 

 than the fourth joint. 



Gammarus anisochir, Kroyer, Tids. [2], i. 283. 



G. (Mcerd) pilosus, Dana, Proc. Amer. Acad. Sci., ii. 213. 



Genus DERCOTHOE, Dana. 



Epirnerce mediocres, 5tce subcequd hihhatce, Uis vix breviores. Margo 

 frontis lateralis juxta oculos scepe valde saliens. Styli caudales postki 

 simplicissimi, sat longi, ramo brevi, subconico, apice paulo reflexo^ e 

 quo spinis duabus brevissimis exsertis. Antennas mperwres scepius 

 longiores, appendiculatod. 



Epimerals moderately large, fifth nearly equally two-lobed, and hardly 

 shorter than fourth. The lateral margin of the front which bears the 

 eye often very salient. Posterior caudal stylets quite simple, rather 

 long, branch short, with a reflexed apex bearing two very short 

 spines. Superior antennae usually the longer, appendiculate. 



The posterior stylets are like those of Pyctilus, and unlike those of 

 any of the preceding genera. The carpus in the legs of the first pair 

 is often as long as the hand, and sometimes longer. The two very 

 short spines at the apex of the posterior stylets are full half as broad 



as long. . 



The name of the genus, from ftp*, to look, alludes to the projection 

 forward of the eyes on a prominence of the front margin either side of 

 the head,— a frequent, if not universal, characteristic of the species. 



