80 PROCEEDINGS OF THE ACADEMY OF [Feb., 



ERYTHEOXYRHOPUS new genus. 



Hypapophyses absent in the posterior dorsal vertebrse. Scales 

 smooth with two apical pits; in species with 19 rows anteriorly 

 reduced to 17 rows posteriorly the IV row is the one that becomes 

 suppressed. Head distinct. Pupil vertical. Maxillary teeth about 

 11 subequal, a short space between them and the two fangs which 

 are behind the eye; anterior mandibular teeth enlarged. A rudi- 

 mentary lung. Hemipenis and sulcus divided, spinous with an 

 apical disk at the termination of each ramus of the organ. 



Type species of this genus is now known as Oxyrhopus trigeminus 

 (Dumeril and Bibron) ; it occurs in the Guianas and Brazil. 



The position of this genus in Cope's classification would be in 

 the Erythrolamprinoe. 



This subfamily of the Dipsadidce may be defined as glyphodonta 

 with the hypapophyses of vertebrse anterior only, hemipenis and 

 sulcus divided, spinous, not calyculate, an apical disk. 



There are three genera all neotropical: — 

 Hemipenis and sulcus bifurcate. 



Disk at the extremity of the sulcus. 



Pupil round Erythrolamprus Boie. 



Pupil vertical Erythroxyrhopus Thompson. 



Disk at one side of the sulcus. 

 Hemipenis with spines in two bands only Lygophis Tschudi. 



The specimens from which the foregoing observations were made 

 are in the Department of Zoology at Leland Stanford Junior 

 University. 



U. S. F. S. Albatross, Dec. 25, 1912. 



