(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 but distinct, the hind margin 
very slightly sinuate. 
The upper 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 Asellns 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 middle. The distal joint is narrow, lunate, (distinctly concave on outer 
margin) about five-sixths the length of the preceding joint, with 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 
first 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 shorter 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 the 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 ( fouet , Sars.) is as broad as long, with about 
eight scattered hairs at tip and several shorter ones on external margin. 
The propodus of the 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 rouuded 
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 A. 
aquaticus , and spined on its distal margin. The female hand is smaller and 
narrower, (width to length as 1 to li) 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 
