SNAKES OF CEYLON. 99 



Two kinds of nematode worms commonly infest the stomach. 

 One of these is seen in clusters with the cephalic extremity 

 attached to the mucous membrane. Each colony — and 

 there may be several — consists of many individuals of very 

 variable size, some of the largest attaining to a length of 

 135 mm. (5J inches). I believe this is the worm described 

 by Von Linstow as Kalicephalis willeyi, but I may be con- 

 fusing this worm with the next species. The second gastric 

 worm, also common, is smaller than the foregoing, and grows 

 to about 34 mm. (If inches). I think it is invariably not 

 attached to the coats of the stomach, but free. I believe this 

 is the worm described by Von Linstow as Heterakis anomala. 



Species of cestodes or tapeworms also infest this snake. 

 I have found many convoluted beneath the mucous membrane 

 of the abdominal cavity and organs, and some of these 

 unravelled reach the length of 250 mm. (10 inches). The 

 lining membrane of the abdominal cavity and its organs are 

 frequently studded with myriads of small, white, ovate 

 bodies, which Professor Shipley pronounced larval forms of 

 a Pterocercus. He suggested that these probably reach 

 their final development inside the Serpent Eagles or some 

 other predacious bird or animal that lives upon snakes. 



(b) Hsematozoa: The red blood cells of the chequered 

 keelback are sometimes invaded by a hsemogregarine, the 

 H&mogregarina mirabilis of Castellani and Willey, which 

 is also found in the erythrocytes of many other snakes. It 

 appears to be somewhat unusual, for its presence was not 

 detected by Dobell in ten specimens submitted to him for 

 examination. 



Lepidosis. — (a) Typical — Rostral : Touches six shields, 

 the rostro-nasal sutures twice, or more than twice, the rostro- 

 internasals. Internasals : A pair ; the suture between 

 them equal to, or nearly equal to, that between the prefrontal 

 pair; subequal to the internaso -prefrontal. Prefrontals: 

 A pair ; the suture between them rather longer than the 

 prsefronto -frontal ; touches the internasal, postnasal, loreal, 

 prseocular, and supraocular. Frontal : Touches six shields ; 

 the fr onto -supraocular sutures twice, or more than twice, the 

 fronto-parietals. Supraoculars : Nearly as long as the 



