322 Records of the Indian Museum. [Vor. XI, 
This latter band spreads out between the eyes. Each band of 
colour consists of very numerous pigment spots. 
The Bhekti on which these parasites occurred was caught in 
the vicinity of Diamond Harbour in the Hughli river near 
Calcutta on February 15, 1915. When placed on deck alive, some 
three dozen parasites were found to be moving over the skin of 
the fish. A few left the host and were picked up from the deck 
of the ship. I have never seen these parasites on any Bhekti in 
the markets and I believe that after the fish are removed from 
water the parasites quickly drop off. 
The parasites are Isopods of the tribe Flabellifera. They are 
included in the family Aegidae and fall in the genus Rocinella, 
Leach, 1818. The characters of this genus are as follows :—- 
‘‘ Form of body resembling that of Aega, though being some- 
what less compact and more depressed. Metasome generally less 
broad, with the terminal segment rounded off at the end and finely 
ciliated. Eyes well developed with very large and conspicuous 
cornea. Antennae slender, the superior ones much shorter than 
the inferior, and with the basal joints not expanded. Epistomal 
plate very small and narrow. Mandibles considerably produced, 
with the cutting edge expanded inside to a linguiform lamella 
(molar expansion) ; palp well developed with the basal joints much 
elongated. Maxillae nearly as in Aega. Maxillipeds with the 
palp composed of only two joints, the terminal one armed with 
strong recurved teeth. The three anterior pairs of legs having the 
propodus more or less expanded and armed inside with strong 
spines, dactylus forming a very large and evenly curved hook. 
The four posterior pairs slender, resembling in structure those in 
Aega. Pleopoda and uropoda normal ’”’ (Sars). 
The conspicuous cornea, the non-expanded base of the 
antennae, the nature of the propodus in the three anterior pairs 
of legs, the evenly armed dactylus on the three anterior pairs of 
legs, and the four-jointed maxillipeds, distinguish the parasite as 
belonging to the genus Rocinella. An outstanding feature of the 
species is the broad elongated head-shield which extends well be- 
yond the bases of the two pairs of antennae. 
The specimens have been deposited in the Indian Museum, 
LITERATURE. 
Stebbing.—History of Crustacea, London, 1893. 
Stebbing.—Ceylon Pearl Oyster Reports, vol. V, London, 1905. 
Sars.—Crustacea of Norway, vol. II, Isopods, Bergen, 1899. 
Hansen.—Bulletin Museum Comparative Zoology, Harvard 
College, vol. XXXI, no. 5, Cambridge, Mass., 1897. 
Richardson.—Proc. U.S. Nat. Museum, vol. 21, 1899. 
Richardson.— do. vol. 23, I9OI. 
Richardson.— do. vol. 27, 1904. 
Richardson.—Bull. U.S. Fish Comm., 1903. 
Moore.— do. do. vol. 20, part 2, 1900. 
