90 SYNOPSES AND DESCRIPTIONS. 



of small yellowish spots ; front part of the snout crossed by a yellowish 

 band ; a black spot on the lips below the eye ; uniform yellowish below. 

 (From descr.) Mexico. 



Contia. 



Baird & Oirard, 1853. 



Moderately elongate, sub-depressed; head little larger than the neck, 

 depressed; tail short, tapering to a point. Eyes small, pupil round. 

 Crown-shields normal. Muzzle protruding. Rostral convex, broad. Nasal 

 entire or divided. A loreal, sometimes united with other shields. One 

 anteorbital. Generally two postorbitals, sometimes one or three. Tem- 

 porals commonly H-2. Labials seven (5—7). Infralabials seven (6 — 8). 

 Scales smooth, rarely keeled, in 15 series. Anal bifid. Subcaudals in two 

 rows. 



(Sonora.) 



Colors in transverse bands ; 



ventrals 149; bands 31 semiannulata. 



ventrals 158 ; bands 41 occipitalis. 



ventrals 158 — 167 ; bands 31 isozona. 



scales keeled on the tail aemula. 



(Contia.) 



Colors 1 not in transverse bands ; 

 oculars 1 — 2; 



labials eight; nasal grooved; 



scales slightly keeled at the tail pygaea. 



labials seven ; flank with longitudinal band ; 

 scales smooth; 



entrals about 161, with black bases 



mitis. 

 ventrals about 145 episcopus. 



CoNTIA SEMIANNULATA. 



Sonora semiannulata Baird & Girard, 1853, Cat. N. A. Serp., 117. 



Body subcylindrical, moderate; head not very distinct from neck, nar- 

 rower on the snout, muzzle produced, elongated; tail short, about one 



