11. TRACK VBOA. 109 



o. 2 (Sc. 37 ; V. 183 ; Ternate. H.M.S. ' Challenger.' 



C. 40). 

 TT. 2 (Sc. 33; V. 175; Misol. 



C. 48). 

 p. 2 (Sc. 33; V. 177; New Guinea, S. of Dr. Comrie [C.]. 



C. 41). Huon Gulf. 



0-. 2 (Sc. 39; V. 187; Solomon Islands. G. Krefft, Esq. rP.1. 



C. 43). 



4. Enygrus asper. 



Erebophis asper, Giinth. Proc. Zool. Soc. 1877, p. 132, pi. xxi. ; 

 Sauvage, Bull. Soc. Philom. (7) ii. 1878, p. 39; Peters Sf Doria, 

 Ann. Mtis. Genon. xiii. 1878, p. 406, pi. iv. ; Hubrecht, Notes 

 Leijd. Mus. i. 1879, p. 19. 



Snout prominent, obliquely truncate ; cauthus rostralis angular. 

 Rostral broader than deep, not visible from above ; head-scales 

 ^ small, irregular, with small tubercles or short keels ; eight or nine 

 scales from eye to eye across the forehead ; eye surrounded by a 

 circle of 13 or 14 scales ; ten or eleven upper labials. Scales 

 strongly keeled, the keels forming oblique lines ; 33 to 39 scales 

 round the thickest part of the body. Ventrals 131-14G ; anal 

 entire; subcaudals 15-21. Reddish brown above, with a dorsal 

 series of large dark-brown, black-edged spots, which may be con- 

 fluent into a zigzag band ; yellowish beneath, uniform or with 

 dark brown spots. 



Total length 730 millim. ; tail 55. 



Misol, Salawatty, New Guinea, and Duke of York Island. 



a. 2 (Sc. 33; V. 140; C. 16). Andai, N. Guinea. 



h. 2 (Sc. 39 ; V. 146 ; C. 20). Duke of York Isl. Rev. G. Brown [C.]. 



(Type.) 

 c. Skeleton. Duke of Y''ork Isl. 



11. TRACK YBOA. 



Trachyboa, Peters.^ Mon. Bert. Ac. 1860, p. 200. 

 Enygrus, part., Jan, Icon. G4n. Ophid. p. 76 (1865). 



Anterior maxillary and mandibular teeth longest, gradually 

 decreasing in size. Head distinct from neck, covered with scales ; 

 no rostral shield ; nostril in a single nasal. Eye moderate, with 

 vertical pupil. Body compressed. Scales keeled. Tail short, pre- 

 hensile ; subcaudals single. 



South America. 



1. Trachyboa gularis. 



Trachyboa gularis, Peters, Mon. Berl. Ac. 1860, p. 200, pi. — . fig. 1. 

 Enygrus gidaris, Jan, Icon. Gen. p. 77, 1. 2, pi. ii. fig. 3 (1861). 



Snout scarcely prominent. Upper head-scales small, convex, 

 keeled, a few on the snout transversely enlarged and smooth ; eye 



