16. TEETANORHINTJS. 281 



1. HydraetMops melanogaster. 



Hydrsethiops melanogaster, Oiinth. I. c. pi. iii. fig-. G. 



Helicops margicatua, Fischer, Oster-Progr. Ak. Gymn. Hamh. 1883, 



p. 11. 

 Hneofasciatus, Sauvage, Bull. Soc. Zool. France, 1884, p. 203, 



pi. vi. fig. 3. 



Eostral as broad as deep, or a little broader, just visible from 

 .■above and in contact witb the intemasal, which is triangular and. 

 longer than broad ; frontal a little longer than broad, as long as 

 its distance from the end of the snout, shorter than the parietals ; 

 Joreal a little longer than deep ; one prae- and two postoculars ; 

 temporals 1+2 or 1 + 3; ten or eleven upper labials, fifth and 

 tsixth or sixth and seventh entering the eye ; three pairs of chin- 

 shields, the anterior in contact with five lower labials. Scales 

 more or less strongly keeled, in 23 rows. Yentrals 143-154 ; anal 

 .divided ; suboaudals 39-49. Dark olive-brown above, with five 

 more or less distinct series of alternating black spots ; a yellowish 

 stripe on each side, from the eye or the angle of the mouth along 

 the first and second rows of scales ; lower parts blacfe. 



Total length 610 miUim. ; tail 100. 



"West Africa. 



.a-d c? (V. 151; 0. 48) & $ (V. 147, Gaboon. (Types.) 



151, 149 ; C. 41, 39, 41). 

 .e. $ (V. 143; C. 48). Cameroons. 



16. TKETANORHINUS. 



Tretanorhinus, Dum.^Bibr. Erp. 04n. vii. p. 348 (1854) ; Jan, Arch. 



Zool. Anat. Phys. iii. 1865, p. 254 ; Bocourt, Le Naturaliste, 1891, 



p. 121. 

 Hehcops, part., Jan, I. c. p. 245. 



Maxillary teeth about 30, subequal ; mandibular teeth subequal. 

 Bead slightly distinct from neck; eye rather s^iall, with round 

 pupil ; nostrils directed upwards, pierced between two nasals. 

 JBody cylindrical ; scales striated and keeled, without apical pits, in 

 19 or 21 rows ; ventrals rounded. Tail moderate ; subcaudals in 

 two rows. Hypapophyses developed throughout the vertebral 

 .column. 



Central America and Cuba. 



Synoj)sis of the Species. 



"Two praefrontals ; posterior chin-shields 



separated from each other by scales ; 



scales in 19 rows 1. variabilis, p. 282. 



'Two prsefrontals ; posterior chin-shields 



in contact with each other anteriorly ; 



scales in 21 rows 2. nigroluteus, p. 282. 



A single praefrontal ; posterior chin-shields 



in contact with each other anteriorly; 



scales in 19 rows 3. moeguardii, p. 283. 



A 



