1923°] AMARAL — NEW GENERA AND SPECIES OF SNAKES 91 



Paroxyrhopus atropurpureus can be distinguished from P. 

 reticulatus by its physiognomy and general color, and by having 

 an entire nasal, 2 postoculars, and supraocular not turned down- 

 wards behind the orbit. 



PLATYINION gen. nov. 



Head not distinct from the neck which is broad; eye moder- 

 ate, with round pupil; nasal divided. Maxillary teeth 5, sub- 

 equal, followed, after an interspace twice as broad as the others, 

 by one large grooved fang situated just below the vertical of the 

 posterior border of the orbit; anterior mandibular teeth long- 

 est. Body cylindrical; scales smooth, with single apical pits, 

 in 17 rows; ventrals rounded. Tail moderate; subcaudals in 

 two rows. 



This genus is allied to Conophis Peters, 1860, from which it 

 differs in the number and disposition of the teeth, the shape of 

 the neck, and in the presence of pits on the scales. 



Platyinion lividum sp. nov. 



Rostral as deep as broad, just visible from above; internasals triangular, 

 as long as broad, shorter than the praefrontals; praefrontals a little 

 broader than long; frontal narrow, more than twice as long as broad, a 

 little longer than its distance from the end of the snout, almost as long as 

 the parietals; nasal divided; loreal longer than deep; 2 praeoculars, lower 

 very small, upper large, reaching the upper surface of the head, but sepa- 

 rated from the frontal; 2 postoculars; temporals, 1+2; 7 upper labials, 

 3d and 4th entering the orbit; 4 lower labials in contact with the anterior 

 chin shields, which are a little shorter than the posterior. Scales smooth, 

 with single apical pits, in 17 rows. Ventrals, 162 + 2/2, rounded laterally; 

 anal divided; subcaudals, 71 pairs. 



Bluish gray above, the scales usually edged with black; uniformly yellow- 

 ish beneath. 



Total length, 730 mm.; tail, 165 mm. 



Type, adult d*, no. 3000 in the collection of the Instituto de Butantan, 

 received alive in November, 1920, from Dorizon, State of Parand, Brazil. 



