294 CEYLOK PEARL OYSTER REPORT. 



Siphoncecetes, Kroyer, 1845. 

 Siplioncecetes orientalis, n. sp. Plate VII., figs. 40. 



Station V., several ; Station LII1., two; and Station LVIII., two specimens. 



Rostrum acute deflexed, as long as the ocular lobes, which are almost rectangular, 

 narrowing distally. Eyes small hut distinct, with about 6 lenses. 



First 4 side-plates acutely angled and fringed with rather long setse. 



Upper antenna' reaching beyond the middle of the 3rd joint of the peduncle of the 

 lower, the 1st and 3rd joints equal; flagellum shorter than the peduncle, 14-jointed. 



Lower antennas almost as long as the whole body, the 1st joint about half as long- 

 as the 2nd, which is a little longer than the 3rd ; flagellum about half as long as the 

 last joint of the peduncle, 3-jointed, the 2nd one-fourth as long as the 1st, the 3rd 

 minute. The whole of the flagellum is armed with a row of 5 or 6 strong recurved 

 spines on each margin of the lower side. The lower side of the 2nd joint of the 

 peduncle is sparsely, and that of the 3rd densely, clothed with long plumose 

 setse (fig. 49. ant. 3 ). 



First gnathopods : 1st joint, hand, and wrist subequal. the hand throughout 

 narrower than the wrist, and narrowing gradually from the base to the end with 

 4 spines on the hind margin ; both hand and wrist setose on both margins. Dactylus 

 with a row of spines on the inner margin, increasing in size distally (fig. 49. gn. 1 ). 



Second gnathopods : much as in S. colletti, Boeck, but the hand narrower, tin- 

 widest part near the base, from which point to the dactylus the hind margin is 

 slightly concave, with 5 spines increasing in size distally (fig. 49. gn. 2 ). Dactylus 

 as in the 1st gnathopods. 



The rest as in S. colletti. 



Length 5 millims. 



The narrowness of the hands of the gnathopods distinguishes this species from the 

 others, but I confess that I am inclined to agree with Della Valle (loc. cit., p. 362), 

 that the points of difference between S. typieus, Kroyer, the original Arctic species, 

 S. colletti, Boeck, and S. pallidus, Sars, are not greater than can be accounted for 

 by age, &c, so that both these species, as well as the present one, might well lie 

 united to S'. typieus. 



Corophium, Latretlle, 1807. 



Corophhrm crassicorne, Bruzklitts. 



Periya Paar Kerrai, 9th November, 1902. Two males, one female. 

 Length 2 '5 millims. 



The only difference observed between this and the European form was that there 

 are 2 spines on the 3rd joint of the lower antennae in the female instead of one. 



