34 



3- Fam. ILYSIIDAE. 



Body round, covered with uniform scales above ; ventrals 

 not or feebly enlarged. Bones of the head more or less solidly 

 united; ectopterygoid present; pterygoid extending to the 

 quadrate; supratemporal small, between the other bones; qua- 

 drate short; praefrontal in contact with nasal. Mandible with 

 coronoid ; jaws and palate toothed. Parts of pelvis the same as 

 in preceding family, ending in a claw, usually visible on each 

 side of the anal opening. 



This family is intermediate between the Boidae and the 

 Uropeltidae, an Indian and Ceylonese group of burrowing snakes. 



Key to the Indo-Australian genera. 



A. No mental groove i. Anomalochilus p. 34. 



B, Mental groove present ,2. Cylindrophis p. 35. 



I. Anomalochilus Lidth. 



(van Lidth de Jeude, in M. Weber, Zool. Ergebn. I p. 180, 1890/91). 



Head small, not distinct from neck, covered with large, 

 symmetrical shields; nostril in a single nasal, touching the 

 second upper labial and forming a suture with its fellow behind 

 the nostril; no loreal or praeocular; a postocular; eye small, 

 distinct from the surrounding shields ; praemaxillary toothless; 

 no mental groove (fig. 18). Body round, covered with smooth 

 scales, in 21 rows; ventrals scarcely enlarged. Tail short and 

 blunt; subcaudals single, paired at the end. 



Distribution. Sumatra. 



A single species. 



I. Anomalochilus weberi Lidth. 



AnoDtalochilus weberi^ v. Lidth de Jeude, in M. Weber, Zoolog. Ergeb. 1890/91, 



p. 181, pi. XV, fig. 1-3. 

 Anomalochilus weberi^ Boulenger, Cat. Sn. I 1893, p. 134. 



Head very small, depressed ; the distance between the corners 

 of the mouth equals that between an angle of the mouth and 

 the tip of the snout; rostral large, more deep than broad; 

 frontal nearly two times as large as the supraocular, quadran- 

 gular, the anterior angle obtuse, the posterior almost right; 

 parietals not enlarged ; postocular small, triangular ; four upper 

 labials, third largest, touching the praefrontal and the eye. 



