238 ANALES DE LA SOCIEDAD CIENTÍFICA ARGENTINA 



snout. Below the eje a large piale rests on the fourth labial ; 

 between ibis and the supraciliary tbere are five small orbitals, 

 decreasing in size backward. Labials eigbt to nine, narrow, ihird 

 and fourlh largest, posterior four boundel above hy a many large 

 smooth scales. Infralabials twelve, anterior largesl, in contact with 

 its opposite behind the naental. A pair of short^ broad submentals, 

 fallowed by others more scale-like. Scales carínate, in 23 rows, 

 vertebral narrow, cúter row broad, faintly keeled. Ventrals 151, 

 broad. Subcaudals 38 pairs. 



Yellowish brown, punctalate with brown; yellowish below. Back 

 with a series of subquadrate light-edged spots of brown (37), more 

 or less oflen divided of the vertebral row into two series, which 

 altérnate posteriorly. Flank with two alternating series of smaller, 

 less distinct blotches. Lower-flank and abdomen with flecks and 

 punctulations of brown. Seven spots on the tail. A band from the 

 zoslril, through the eye, to the angle of the mouth. A blotch on the 

 prefrontal región. A pair of spots on the parietal región, diverge 

 posteriorly, then approach again on the nape. Posterior labials 

 with brown margins. Chin clouded with brown. Coloration 

 closely resembling that of light-colored specimens of Heterodon 

 platyrhinus . 



Rhinocerophis agrees in pit, fangs, squamation, bifid subcaudals, 

 and minor characters, with Copinas Meur. {Bothrops Wagl.), in which 

 it might be placed as a sqbgenus. It differs in the rostral protube- 

 rance, the consequent upward extensión of the rostral shield, and 

 great development of the caudal spine. 



The specimen described was secured by the «Hassler» Expedition 

 al Puerto San Antonio, Eastern Patagonia. The jar in which it is 

 kept bore the ñame Bothrops nasus, for which I am unable to 

 find authority or description ». 



Hemos reconocido esta serpiente entre ejemplares que posee el 

 Gabinete de la Universidad y que provienen del Sur de la Provincia 

 de Buenos Aires. 



En la enumeración de los reptiles y anfibios del viage del Dr. D. 

 Eduardo L. Holmberg (véase: Actas de la Academia Nacional de 

 Ciencias de Córdoba. T. V, p. 96. — 1884), hemos tenido ocasión 

 de hablar de esta especie;, suprimiendo el género ó subgénero 

 Rinocerophis de Garman, por no haber caracteres suficientes gené- 

 ricos. El apéndice córneo de la cola es variable en el género 



