A New Genus of Fresh-water Isopoda. 125 



with a well marked cylindriform appendage outside tlie third 

 joint of peduncle. First maxillae with outer lobe tipped with 

 stout pectinated spines. Second maxillae with outer twin lobes 

 tipped with finely pectinated setae. Maxillipeds normal, second 

 and third joints of " palp " not greatly expanded. Legs simple, 

 biunguiculate, ambulatory, similar to each other in form. 

 Uropods largely developed, cylindriform ; outer ramus much 

 shorter than inner one. Pleopods normal ; operculum of female 

 large ; middle piece of male operculum slightly, or not at all, 

 dilated at tip. 



Remarks. — This genus unites in a measure the characters of 

 latiira imd/aniropsis as detined by 8ars ;^ as well as possessing 

 characters dissimilar from each. 



Vvom /an if a it diifers : — (1) The superior antennae are not 

 composed of " numerous short articulations." (2) The second 

 pair of maxillae have the outer lobes tipped with pectinated, not 

 " simple setae." (3) The first pair of legs have not the carpus 

 large and strongly prehensile. (4) The dactyli of the legs are 

 not 3-unguiculate. 



From Janiropsis it differs : — (1) The maxillipeds have not 

 the " second and third joints of the palp very much expanded." 

 (2) The first pair of legs of the male are not " remarkably 

 developed, prehensile, much longer than any of the other pairs, 

 with the carpal joint fusiformly developed." (3) The middle piece 

 of the male operculum is not " remarkably dilated at the tip." 

 (4) The uropoda are not " much shorter" than those of /anira. 



It is peculiarly characteristic in : (1) The form of the male, (2) 

 The legs are subequal and similar in form in both sexes. The 

 dactyli, although biunguiculate, as in faniropsis terminate in a 

 long simple unguis, near which is a small lateral one. (3) The 

 caudal segment is very large. (4) The uropoda are cylindriform 

 and have the outer ramus very short. 



Janirella pusilla, n. sp. 



Specific Cliaracter. — Female. (Fig. 1) Body oblong-oval, 

 three times longer than broad, outer margins of all segments 

 except front of cephalon fringed with short stout spinules — 



1 Loc. cit. 



