1918.] T. Southwell & B. Prashad : hulian Fish Parasites. 353 



The arrangement of the spines on the first four pairs is as follows : — 



First exopod 



„ endopod 

 Second exopod 



„ endopod ... 

 Third exopod 



„ endopod 

 Fourth exopod 



„ endopod ... 



Colour of specimens preserved in spirit milky-white, with mimito 

 black pigment spots scattered on the dorsal surface of the carapace. 



mm. 

 Length ... ... ... ... ... 1-22 



Length of carapace ... ... ... ... 0-71 



Breadth of carapace ... ... ... ... 0-39 



Length of egg-strings ... ... ... ... 1-09 



Breadth of egg-strings ... ... ... 0-14 



From the gills of Wallago offu (Bl. Schn.), Mirpur, district Dacca, 

 Bengal, 3rd June, 1917. 



Many specimens. Types in the collection of the Zoological Survey 

 of India, numbered ^y^^. 



No males were obtained. 



Ergasilus hamiltoni, sp. nov. 

 (Plate XIV.) 



Female tFig. 1). — Cephalothorax a little more than half the entire 

 length and one and a half times as long as broad. First thoracic segment 

 distinctly separated from the head by a groove. Head transversely 

 elliptical, with evenly rounded anterior margin. First thoracic segment 

 three times longer and a little wider than the head, quadrilateral in 

 outline, with acutely rounded corners. Second, third, fourth and fifth 

 thoracic segments diminishing regularly in length but about the same 

 width. Sixth, or the genital segment, thrice as wide as the fifth thoracic ; 

 barrel-shaped, with rounded sides. 



Abdomen three-jointed, the segments diminishing regularly in 

 length and width, the terminal one deeply notched in the middle. Anal 

 laminae more or less squarish, smaller in width than the last abdominal 

 segment, and tipped with two setae, the inner of which is three times the 

 length of the outer. Egg sacs two-thirds the length of the entire body, 

 ellipsoidal ; eggs large, arranged in five longitudinal rows, 60-65 in each 

 sac. 



First antennae (fig. 2) six-jointed, joints diminishing regularly in 

 length and breadth ; all segments setose. The second antennae (fig. 3) 

 arc attached to the ventral surface just posterior to the bases of the first 

 })air. They are four-jointed, first or basal joint large and swollen, 

 the second joint one and a half time as long as the first, third joint 



