82 SYNOPSES AND DESCRIPTIONS. 



short, broad; prefrontals and internasals often united. Rostral large, 

 prominent, produced backward between the internasals or prefrontals, 

 convex, sometimes resembling that of Heterodon. Nasal usually entire 

 and grooved behind the nostril, sometimes divided or without the gropve. 

 Oculars 1 — 2. Scales smooth, broad, in 17 rows. Anal divided. Sub- 

 caudals in two rows. (Anterior labials, rostral, and nasal sometimes 

 united.) 



Internasals and prefrontals not united; 



rostral separating internasals but slightly ; 



prefrontal and labials in contact frontalis. 



rostral separating internasals, but not reaching frontal 



cana. 

 Internasals and prefrontals united; 



nasal and anteorbital in contact nasus. 



rostral not reaching the frontal; 



loreal generally distinct maculata. 



rostral reaching the frontal ; 



loreals fused with prefrontals ; 



back with black cross bars variegata. 



back blackish-olive olivacea. 



FlCIMIA FRONTALIS. 

 Toluca frontalis Cope, 1864, Pr. Ac. N. Sc, Phil., 167. 



Muzzle prominent, pointed, slightly narrowed. Prefrontals slightly 

 separated by the rostral. Nasal long. Frontals in contact with labials. 

 Preocular low, narrow. Two postoculars, lower barely in contact with 

 one temporal. Seven upper labials ; eye over third and fourth ; seven 

 lower. Parietals longer than frontal. Anterior suture of frontal a little 

 longer than straight lateral. Scales in 17 rows, equal, thin. One pair 

 of short submentals. Ventrals 144. Anal bifid. Subcaudals 44 pairs. 

 Total length 10^ inches ; tail, 1;° inches. 



Greyish-brown, more rufous medially, with about thirty-six rhombic 

 dark-edged spots of brown, six scales wide and four long, the angles of 

 which are produced as vertical lateral bars. Spots becoming similar to 

 cross-bands posteriorly, separated by a pale spot on the vertebral line. 

 A brown cross-band across prefrontals and frontals; a longitudinal band 

 on each occipital and side of nape. (Cope.) From Colima, Mexico. A 

 doubtful species. 



