GREGARIOUS CRUSTACEA FROM CEYLON. 
25 
Family : COROPHIID^E. 
GOROPHIUM , Latreille. 
1806. Gorophium, Latreille, Genera Crustaceorum, vol. I., p. 58. 
1888. Gorophium , Stebbing, Challenger Amphipoda, Reports, 
vol. XXIX., pp. 79, 1670. 
1893. Gorophium , Della Valle, Gammarini, p. 362. 
1894. Gorophium, Sars, Crustacea of Norway, vol. I., pt. 27, 
p. 612. 
1900. Gorophium, Chevreux, Amphipodes de 1’Hirondelle, 
p. 109. 
The species now known of this genus are rather numerous, all 
possessing in common marked features of general resemblance, 
yet separable into two groups by the circumstance that in some 
the fourth, fifth, and sixth segments of the pleon are distinct, and 
in others consolidated into a single piece. 
GOROPHIUM TRIJENONYX, n. sp. 
Pi. 6a. 
The rostral point is little produced. The side plates of the 
first perseon segment are apically fringed with six plumose setae. 
The pleon is fully segmented, and has the lateral margins of the 
first two segments fringed with plumose setae. 
The eyes are small and dark. 
The first antennae have the flagellum shorter than the peduncle, 
about twelve-jointed in the male and nine-jointed in the female. 
In the latter the third joint of the peduncle is half as long as the 
second, and the second half the first, but in the male the third 
is less than half the second, and the second more than half the 
third. 
The second antennae are robust, in the male strongly setose, with 
the penultimate joint of the peduncle produced into a large curved 
tooth, with a small one beside it at the base on the inner side; in 
the female this joint is as usual much shorter, furnished with 
numerous spines, but without teeth. 
In the mouth organs it may be noticed that the narrow inner 
plates of the maxillipeds are fringed with spines, fifteen in 
number, along the whole inner margin. 
The first gnathopods are of the usual pattern, with the third 
and fifth joints densely setose, the fifth tapering distally, the 
shorter oblong sixth fully as wide at the rounded spinulose palm 
as at the base, its front margin fringed with slender spines : the 
finger smooth, small, curved, acute. 
E 
8(3)04 
