282 CEYLON PEARL OYSTER REPORT. 



L. websteri. Another from East Cheval Paar appears to be a Lemboides, Stebbing, 

 ' Ann. and Mag. Nat. Hist.,' Ser. 6, vol. 16 (1895), p. 209, plates ix. and x., but both 

 are too imperfect for description. 



Aora, KiioYER, 1844. 

 Aora gracilis (?), Sp. Bate. 



Pearl oyster washings, Gulf of Manaar. 



A very small (2 millims.) and imperfect male from Muttuvaratu had the charac- 

 teristic gnathopods of this species, and a female, with ova, length 2'5 millims., from 

 East Cheval Paar may possibly belong to it. 



Gammaropsis, Lilljeborg, 1854. 

 Gammaropsis zeylanicus, n. sp. Plate VI., figs. 41. 



Generally distributed round the coast of Ceylon. 



Head as long as the first 2 segments. Ocular lobe produced to more than one- 

 third of the length of the 1st joint of the upper antennae, subangular ; the extremity 

 generally entirely occupied by the eye, which is dark and variable in size and shape. 



Hind margin of the 3rd pleon segment rounded. Urosome about as long as the 

 last pleon segment, its 1st segment dorsally depressed. 



Upper antennae more than half as long as the body and longer than the lower, the 

 peduncles subequal ; 1st joint twice as thick and two-thirds as long as the 2nd, 

 which is longer than the 3rd ; flagellum subecpial to the peduncle, with about 

 14 joints; appendage reaching the middle of the 5th joint of the flagellum, 5-jointed, 

 the last joint the longest. 



Lower antennae: 2nd and 3rd joints subequal, longer than the 11-12-jointed 

 flagellum. Both pairs of antennae are sparsely setose. 



Mouth organs and maxillipeds normal. 



First gnathopods (female) : side-plates rhomboidal, front not jjroduced, angles 

 rounded ; 1st joint subequal to the next 3 ; wrist subequal to the hand in length and 

 width, very setose on the side and hind margin ; hand oval, palm undefined, with 

 setiferous ridges on both margins ; dactylus rather long, serrate. In the immature 

 male from the same tube as the female (Station LVIII.) the 1st joint is stronger and 

 has 3 strong curved pectinate setae at the end of the hind margin ; these were not 

 seen on the female or the adult male. In this last the front margin of the side-plates 

 is considerably produced to a rounded acute angle and the 1st joint is very stout, 

 with scattered setae along the hind margin (fig. 41. gn. 1 ? ). 



Second gnathojx>ds (female) : side-plates as in the 1st pair, but rather wider ; 1st joint 

 strong, the margins subparallel, considerably longer than the next 3 joints ; wrist 

 triangular, about half as long as the hand ; this is oval, palm only defined by a blunt 

 spine a little beyond the middle of the hind margin, which, as well as that of the 



