1918.] T. SouTHWEl.L & B. Prashad: Parasites of HiJsa. 8^ 



The cysts measured about 64 mm. in length, the head being 5-7 mm. 

 long by 3-1 mm. broad, whilst the tail varied in length from 58 mm. to 

 60 mm. The tail was an elongated tapering structure. The cysts 

 were of a milky-white colour, the head being formed of stout fibrous 

 tissue, whilst the tail portion consists of a thin membrane enclosing an 

 albuminous fluid. 



On one of these cysts being dissected out it was seen that the head 

 portion contained a second cyst (Y), almost cylindrical in shape, trans- 

 parent, and 3 mm. in length. 



This second cyst, on being opened, was found to contain the worm 

 (plate iv, fig. 9), which showed four fully developed bothridia and 

 four proboscides, with a neck and an undifferentiated part posteriorly, 

 which terminated in a vesicle. 



The parasites were not very numerous in the specimens of Hilsa 

 which we examined. 



Literature cited — 



(1) Linton, E.' — Notes on Entozoa of marine fishes. Report 



U. S. Fish Coimn. for 1887. Washington, 

 1891. 



(2) Southwell, T." — Ceylon Marine Biological Reports, Part VL 



Colombo, 1912. 



(3) Southwell, T.' — On some Indian Cestoda, Part L Rec. Ind^ 



Mus., Vol. IX, Part V, 1913. 



HI. A DESCRIPTION OF A CESTODE PARASITE OF DOUBTFUL 

 SYSTEMATIC POSITION, FROM THE MESENTERY AND 

 LIVER OF HILSA. 



I. Introdx'ction. 



In the following paper we propose describing a parasite which, though 

 of small size, appears to be of very great systematic importance, and 

 which further reproduces itself in a manner not before known amongst 

 the Cestoda. 



The parasites were found first at Khulna in the mesentery of 

 Hilsa. The mesentery (m), binding up the various coils of the intes- 

 tine, was infected so very heavily as to appear something like a massive 

 liver-like organ in which the various coils of the intestine appeared 

 merely as tubes embedded therein. The infection had further spread 

 to the liver [L (i)] which, in most specimens examined, was also heavily 

 infected, though only in part (plate v, fig. 1). 



Since the initial observations were made, the parasites have been 

 found to be widespread. They were formd in Hilsa examined by us 

 from Goalundo, Sahebgunj, Kalna, and Calcutta. The infection is of 

 such a heavy nature that, although more than a hundred specimens 

 have been examined, not a single one was found which was not similarly 

 infected. Continuous observations on living and preserved material 

 were made at Khulna and Kalna and in the Fisheries Laboratory 

 in the Indian Museum, over a considerable length of time. It has thus 



