I 12 ) 



dered laterally with short hairs. The large abdominal segment is preceded 

 by two very short ones. The abdomen is about as long as the last two 

 thoracic segments, the hind angles rounded bixt distinct, the hind margin 

 very slightly sinuate. 



The dipper antennae reach to the tip of the penultimate joint of the 

 pedicel of the lower. Pedicel and flagellum about equal, latter ten to 

 twelve-jointed, bearing a slender olfactory club at tip of each of the four or 

 five joints preceding the last. Joints of pedicel sub-equal in length, but 

 the first twice as large as the second. 



The lower antennae are about two-thirds as long as the body in the fe- 

 male, in the male somewhat longer. Pedicel about one-third flagellum, 

 five-jointed, fifth and sixth joints each longer than the basal three together. 

 The flagellum contains 75 to 80 joints. The mandibles are almost exactly as 

 in Asellus aquaticus. The posterior dental plate of the left mandible is 

 nearly as wide as the anterior. The hairs of the marginal fringe are more 

 numerous on the right mandible than on the left, and the anterior eight are 

 toothed instead of plumose. 



The mandibular palpus is slender, the basal joint a little shorter than 

 the second. On the latter the external angulation is considerably behind 

 the tniddle. The distal joint is narrow, lunate, (distinctly concave on outer 

 margin) about five-sixths the length of the preceding joint, wnth about 20, 

 jointed, plumose, marginal hairs, similar to those on the distal half of outer 

 margin of preceding joint. The two plates composing each mauilla of the 

 Jirst pair are equal in length. The inner is three-fourths as wide as the 

 outer, terminating in five plumose hairs. The outer terminates in twelve 

 strong spines, of which the five outer are stronger and simple, and the seven 

 inner irregularly and bluntly toothed near their tips. The posterior 'maxillae 

 as in Asellus aquaticus. The shortcf internal hairs on the two outer plates are 

 expanded transversely to the plane of the plate and hollowed lengthwise on 

 the inner face, giving each hair the form of a racing-shell, while both edges 

 of the hair are coarsely toothed. The basal joint of iho: palpus of the max- 

 illiped is quadrate, the fourth joint is about as long as the second and third 

 together. The inner margins of the fourth and fifth are provided with very 

 long hairs. The flagellum {^fouct, Sars.) is as broad as long, with about 

 eight scattered hairs at tip and several shorter ones on external margin. 

 The propodus oi i\\Q first pair of feet in the male is very large, broad-oval, 

 two-thirds as wide as long. A strong curved spine is situated at the proximal 

 end of the palm, and two truncate, stout teeth separated by a rounded 

 emargination, near the distal end. The dactyl is strongly curved, es- 

 pecially at base, its inner edge serrate with six acute teeth appressed towards 

 tip. The length of the terminal claw is more than one-third that of the en- 

 tire dactyl. The convex margin of the dactyl bears a few scattered hairs, 

 and a cluster of four or five near the tip. The carpus is small as in ^. 

 aquaticus, and spined on its distal margin. The female hand is smaller and 

 narrower, (width to length as 1 to I4) the palmar margin concave, the pair 

 of truncate teeth replaced by a single smaller conical one which is some- 

 times obsolete. The other differences are trivial. The legs become longer 



