NATURAL SCIENCES OF PHILADELPHIA. 499 



S. millepunctatus, Hallowell. 



Dorsal scales very minute;* occipital granular; frontal keeled. Muzzle 

 rather short. Auricular orifice smaller than digital expansion. Light brown, 

 spotted with darker brown ; a post axillary, a loreal, two postocular and a 

 median occipital brown line. A transverse crural spot, brown bordered pos- 

 teriorly with white. 



Hab. Nicaragua. Mus. Philadelphia, Washington. 



S. casicolus, Cope. 



Dorsal scales very minute; occipital granular, frontal keeled. Supranasal 

 plates as long as broad. Muzzle elongate. Auricular aperture larger than digital 

 pallet. Dark brown rufous, with three distant, transverse, dorsal blotches, 

 bordered with lighter ; the anterior or interscapular indistinct. A dark 

 spot upon the nape, bounded by two light dots. Numerous short longitudinal 

 white lines upon the dorsal and lateral regions ; none upon the head. A 

 loreal and three postocular dark lines. Beneath whitish, chin and sides of 

 neck punctulated with rufous. 



Hab. Region of the Truando, New Granada. Mus. Washington. 



bb. Inferior labials (anterior to posterior border of orbit) six ; muzzle more 



acute. 

 S. oxyrhinus, Gosse. 



Muzzle acute, depressed ; supranasals in contact. Above light brown, with 

 numerous conspicuous black dots (sometimes confluent, according to Mr. 

 Gosse) ; two light dots, bordered with black, at the base of tail. Belly light 

 brown, throat dotted. Tail long. Pupil round. 

 Hab. Jamaica. Mus. Washington. 



S. a 1 o p e x, Cope. 



Muzzle very acute, profile sloping regularly from the frontal region. Supra- 

 nasal plates separated. Pupil apparently elliptic. Tail much longer than body. 

 Dorsal scales smaller than in oxyrhinus. Above rufous gray, closely ver- 

 miculated with longitudinal rufous lines ; tail and extremities spotted with 

 the same. Beneath pale brownish, faintly vermiculated with rufous brown on 

 the gular region and the sides of the neck ; many of the abdominal and femoral 

 plates margined with the same. 



Hab. Near Jeremie, Hayti. Mus. Cambridge. 



aa. Dorsal scales equal to the ventral. 



b. Occipito-nuchal scales larger than those on the muzzle; palpebral spine 



absent or rudimentary. 



S. richardsonii, Gray. 



Cranial and gular scales tuberculiform. Supranasal plates narrow; sym- 

 physeal broad posteriorly, bordered by three scales. Dorsal scales ia about 

 eighteen rows, their keels very strong. Pupil slightly elliptic, (Gosse.) Color, 

 inspirits, light brown, with seven narrow, irregular, brown cross bands, bor- 

 dered behind with paler ; these are the outlines of broad bands, which are, in 

 life, according to Mr. Gosse, reddish lilac. These are succeeded by darker 

 bands on the tail, which become black at its extremity. Limbs annulated. 

 A narrow cross band on the nape, two on the occiput. A light curved frontal 

 cross band ; a similar one anterior to the eye, one posterior, one infero-posterior 

 to it ; a transverse postfrontal band. These headbands are bright yellow in 

 life, (Mr. Gosse.) 



Hab. Jamaica, Mus. Washingtou. 



* Dr. Hallowell's statement, Pr. A. N. S., 1860, p. 480, that the ventral scales are 

 keeled, appears to be incorrect. 



1861.] 



