AMPHIPODA. 249 



Leptophoxus, G. 0. Saks, 1895. 



Leptophoxus uncirostratus (Giles). 



Phoxus uncirostratus, GrlLES, 'J. Asiat. Soc. Bengal,' vol. 50, Pt. II., 1890, p. 65, pi. ii., fig. 2. 



Station XXXVII., one old female ; length, 10 millims. Station LVIIL, one young 

 female. 



Ampelisca, Kroyer, 1842. 

 It will lie useful to give here a synopsis of the following species of the genus : 



Upper antennas extending beyond the peduncle of the lower by more than 3 joints 

 of the flagellum. A. tridens, n. sp. 



Upper antennae extending beyond the peduncle of the lower by less than 3 joints 

 of the flagellum. 



Lower antennas reaching beyond the pleon. A. scabripes, n. sp. 



., not reaching beyond the pleon. A. brack ijceras, n. sp. 



Upper antennas not reaching the end of the peduncle of the lower. 



Third uropods ovate ; inner margin of outer ramus distinctly serrate. 



Posterior angle of 3rd pleon segment acute, much produced, and upturned ; head 

 angular below. A. brevicornis, Costa. 



Posterior angle of 3rd pleon segment scarcely produced or upturned ; head rounded, 

 narrow ; one large red eye on each side of the head. A. cyclops, n. sp. 



Third uropods lanceolate, outer ramus not serrate. A. chevreuxi, n. sp. 



Ampelisca tridens,* n. sp. Plate II., tigs. 11, and Plate IV., figs. 11. 



Generally distributed round the coast of Ceylon. 



Head rather longer than the first 2 segments, not much produced, with a distinct 

 but rounded lateral angle, just below which the lower and larger eye is placed ; the 

 other is close to the base of the upper antennas (Plate II., fig. 11. a). 



Third pleon segment with the hind margin slightly convex ; the posterior angle 

 acute, scarcely upturned ; the 2nd pleon segment lias the hind margin more convex 

 and the angle less produced. 



First urosome segment with a deep dorsal depression, on which are 3 carinas, each 

 ending in a knob-like prominence. The 2nd segment is also dorsally depressed, with 

 the sides elevated distallv, forming a rounded prominence on each side of the base of 

 the telson. The 3rd segment is hidden by the 2nd (Plate IV., fig. 11. ur.). 



Upper antennas reaching to about half the length of the flagellum of the lower, the 

 peduncle to a little beyond the middle of the 2nd joint of its peduncle. 



* From the three prominences on the 1st urosome segment. 



2 K 



