Chilton. — On some Subterranean Crustacea. 179 



appear to have been found in Nijihargus 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 antennae 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 antenna about as long as that of the upper, 

 the last two joints equal in length with then- inferior edges setose ; 

 flagellum longer than the peduncle. Appendage of the mandible with three 

 joints, the second being longer than the other two. Gnathopoda subequal, 

 propodos long ovate, finger curved. Last three pairs of pereiopoda very 

 long, 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 sets 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 setae and a number of delicate plumose setae. Telson double, each 

 part having the posterior end rounded and tipped with two or three setae. 



Colour — transparent. 



Length (largest specimen), "65 inch. 



Hah. Pump at Eyreton. 



This species is readily reeognized by the great length of the last pair of 

 pleopoda and of the last three pairs of pereiopoda. It is not very common, 

 but it is larger than any of the other species. 



DESCEIPTION OF PLATE IX. 

 Calliope subterranea, female, X 9. 



,, „ Base of flagellum of upper antenna showing the 



rudimentary secondary appendage. 

 ,, „ Sensory seta from peduncle of upper antenna of male. 



„ „ Portion of flagellum of upper antenna of male 



showing sensory capsules a, and sensory set© b. 

 „ ,, Mandible. 



,, „ Second maxilla. 



„ „ Maxillipede. 



„ ,, First gnathopod of male. 



,, „ Second gnathopod of male. 



„ „ Telson. 



* See Ann and Mag. Nat. Hist., ser, 4, vol. six., 1877, p. 243, 



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