762 



EEPORT OP i^ATIONAL MUSEUM, 1898. 



outer sometimes smooth. Scales on the back quite linear anteriorly; 

 posteriorly they are much broader. Color yellowish gray, or brown, 

 with about twenty-eight dark dorsal blotches from head to anus, and 

 fifteen half rings on the tail. One or two lateral rows. Beneath yel- 

 lowish. A dark band across the forehead in front of the vertical, con- 

 tinued through the eye to the angle of the mouth. 



Frontal plate hexagonal, narrower behind; longer than broad; angles 

 all distinct, lateral outlines straight. Prefrontal large, the lateral 

 angle extending down to the loreal; the two prefrontals separated an- 

 teriorly by the azygos, or postrostral. Interuasals smaller, entirely 

 separated by the azygos. Eostral with the outline spherical angled, 

 subacute at the apex, its upper surface compressed into a sharp ridge, 



Fig. 165. 



HeTERODON PLATYRniNUS LaTREILLE. 



Black specinieu. 



which, prolonged backward between the nasals and the prefrontals, 

 connects with the azygos. This is linear, subpentagonal, acute-angled 

 behind, where it wedges between the prefrontals. Superciliaries large. 

 Scales behind the head distinctly carinated. Eye large. Line con- 

 necting tip of rostral with the i)ostinferior corner of the last labial 

 passes over the lower part of the eye. A triangular nasal, with the 

 corners rounded, joined by its ax)ex to the exterior angle of the pre- 

 frontals. Ko inferior nasal. Nostrils valvular, situated entirely in 

 the posterior nasal, the anterior edge formed by the anterior nasal. 

 Labials eight above; all higher than long, sixth largest, the third to the 

 sixth in contact with the suborbitals; two large temporal shields above 

 the three posterior labials. Temporals, three in the first row in eight 

 specimens, 4-3 in one, and four on both sides in four. Center of th^eye 



