Cumton.—On some Subterranean Crustacea. 179 
appear to have been found in Niphargus puteanus by M. Alois Humbert. * 
The form of the mandibles, second maxilla and maxillipedes will be readily 
understood from the figures given. 
Genus Gammarus. 
(Brit. Mus. Cat. Amphip. Crust., p. 203.) 
Gammarus fragilis, sp. nov. Plate IX., figs. 11 to 18. 
Eyes none. Superior antenne about as long as the body ; first joint of 
the peduncle about as long as the next two together, the third joint being 
only one-third the length of the second; secondary appendage with about 
five joints, the joints of the flagellum increasing considerably in length 
distally. Peduncle of inferior antenne about as long as that of the upper, 
the last two joints equal in length with their inferior edges setose ; 
flagellum longer than the peduncle. Appendage of the mandible with three 
jomts, the second being longer than the other two. Gnathopoda subequal, 
Doan long ovate, finger curved. Last three pairs of pereiopoda very 
ng, increasing in length from before backwards, the last pair reaching as 
far as the last pair of pleopoda. Last three segments of the pleon with 
stout sete on their posterior dorsal margins. Of the three posterior pairs 
of pleopoda the first reaches as far as the end of the second, but the third is 
very long ; its two branches are equal in length and supplied with numerous 
stout sete and a number of delicate plumose sete. Telson double, each 
part having the posterior end rounded and tipped with two or three sete. 
Colour—transparent. : 
Length (largest specimen), *65 inch. 
fat, Pump at Eyreton. 
This species is readily reeognized by the great length of the last pair of 
oe and of the last three pairs of pereiopoda, It is not very common, 
ut it is larger than any of the other species. 
ne DESCRIPTION OF PLATE IX. 
8. 1. Calliope subterranea, female, X 9. 
Hes 
0 ” 
ri rudimentary secondary appen a 
eg 8. ” Sensory seta from peduncle of upper antenna of male. 
1B. 4. ” Z. Portion of flagellum of upper antenna of male 
| showing sensory capsules a, and sensory sete 0. 
Fig. ‘ ” " Mandible. 
Fig. 3 ” oo Second maxilla 
Fig, g: ” - Maxillipede. 
Fig. ‘ ” First gnathopod of male. 
rn ae © Second gnathopod of male. 
- Telson. 
” Pe 
‘ eee eas aie 
* See Ann and Mag. Nat. Hist., ser, 4, vol. xix., 1877, p, 248, 
