104 ccECiinD^. 



riorly ; the posterior third of the length with intermediate annuli, 

 which are first lateral only, then complete above, entirely complete 

 on the terminal inch : the whole number will then be about 170 

 annuli. Perm of body rather slender; tail depressed attend, short, 

 acuminate. Colour dark plumbeous, annuli yellow-lined; head 

 yellowish brown." 

 Belize. 



11. CHTHONERPETON. 



Chthonerpeton, Peters, Mon. Berl. Ac. 1879, p. 940. 



Squamosals separated from parietals. Two series of teeth in the 

 lower jaw. Tentacle flap-shaped, the tentacular groove crescent- 

 shaped, situated between the nostril and the eye. No scales. 



South America. 



1. Chthonerpeton indistinctum. 



Siphonops indistinctus, Seinh. 8^ Liith. Vidensk. Meddel. 1861, p. 203; 



A. Bum. Mim. Soc. Cherb. ix. p. 318. 

 Chthonerpeton indistinctum, Peters, Mon. Berl. Ac. 1879, p. 940. 



Teeth small, numerous, subequal. Snout rounded, prominent ; 

 eyes distinct ; tentacle between the nostril and the eye, below the 

 line which would unite them. Body moderately elongate ; circtdar 

 folds 78 to 100, rather indistinct, incomplete. Tail indistinct, 

 rounded. Blackish grey, with or without irregular lighter spots. 

 Total length 320 millim. ; greatest diameter of body 12 millim. 



Porto Alegre ; Buenos Ayres. 



2. Chthonerpeton petersii. (Plate IX. fig. 2.) 



Teeth small, numerous, subequal. Snout rounded, moderately 

 prominent ; eyes not distinct through the skin ; tentacle close to 

 and behind the nostril. Body elongate ; 145 circular folds, com- 

 plete except the anterior 28, which are interrupted on the dorsal 

 and ventral line. Tail indistinct, rounded. Uniform dark olive- 

 grey, the eyes indicated by a whitish spot. Total length 620 millim. ; 

 greatest diameter of body 16 millim. 



Upper Amazon. 



a. Adult. Upper Amazon. 



