Mr. G. A. Boulenger on the Genus Pseudoxyrhopus. 311 



which is twice the length of the eye or j the total length of 

 the headj and conspicuously prominent beyond the mouth. 

 Eyes circular, set high up on the side of the head, deep 

 beneath a small transparent area of skin, a diameter and a 

 half apart. 



Anterior nostril a short wide tube situated inferiorly at the 

 tip of the snout. Posterior nostril a large circular foramen 

 just above the anterior orbital angle. 



Mouth subrostral ; its angle reaching slightly beliind the 

 vertical through the anterior border of the orbit ; the jaws 

 completely hidden by the very thick inflated lips. Villiform 

 teeth in broad bands in the jaws, and in a broad, confluent, 

 triangular patch covering the palate. Tongue free. 



Gill-openings small, widely separated foramina, hardly 

 larger than the eye; four gills with narrow laminse and coarse 

 lamellge and wide clefts; no gill-rakers. 



Integument thick, coriaceous, scaleless, investing the 

 vertical fins and completely concealing their rays. The lateral 

 line traverses the middle of the body. 



Vertical fins confluent ; the dorsal begins a distance behind 

 the occiput equal to the length of the postrostral portion of 

 the head, or just behind the level of the tips of the pectorals 

 when laid full back. The anal begins immediately behind 

 the vent. Pectorals small, pointed, equal in length to the 

 rostrorbital portion of the head. 



Stomach with a cul-de-sac of moderate size ; intestine wide, 

 little convoluted ; liver large, indistinctly lobated, embracing 

 the oesophagus. Air-bladder very large, with very thick 

 spongy walls and a small central cavity. 



Colours in the fresh state : — Body and fins uniform purple- 

 black. 



One female specimen, 17 inches long, with mature ovaries. 



Station 104, 1000 fathoms. 



I am greatly indebted to Professor Wood-Mason for 

 counsel and advice. 



XXXV. — On the Ophidian Genus Pseudoxyrhopus, Gthr. 

 By G. A. Boulenger. 



A CURIOUS snake from Madagascar was described by Jan in 

 1863 under the name of Homalocephalus^ which name, being 

 preoccupied in entomology, was changed by Giinther to 

 PseKdoxyrho-pus in 1881. Jan placed his new genus among 



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