54 SYNOPSES AND DESCRIPTIONS. 



Elaphis obsoletus, pi. IV., Jig. 2. 



Coluber obsoletus Say, 1823, James' Acct. of Long's Exp. I, 140. 



Long, slender, tapering to head and tail, compressed; belly flat, angled 

 at the edges; neck small; head large, broad behind, narrow in front of 

 the eyes, depressed, with flat crown ; tail short, near one fifth of the total, 

 slender. Eye moderately large, over the fourth and fifth labials, pupil 

 round. Mouth-cleft deep, curved. Head-shields nine, broad. Frontal 

 broad anteriorly. Prefrontals bent down on the side of the face. Snout 

 prominent. Rostral large, a little broader than high, convex. Nasal in 

 two parts, nostril between. Loreal low. One large anteorbital. Post- 

 orbitals two. Temporals 2-1-3. Labials eight, seventh largest. Infra- 

 labials twelve, sixth largest. Submentals two pairs, the hinder separated 

 by small scales. Scales lozenge-shaped, extremity rounded, in 27 rows, 

 two or more of the outer smooth, medial keeled, those on the flanks more 

 faintly. Ventrals about 233. Anal entire. Subcaudals about 85 pairs. 



Light greyish-brown, reddish in life, varying to black. In light colored 

 specimens of small size there is a dorsal series of about forty large spots, 

 with darker edges, separated by narrow spaces of light color. On the 

 flank three series of alternating spots, the spots in each half as large 

 as the next above. On the extremities of the abdominals a series of twice 

 as many quadrate spots. On each side of the median line of the belly a 

 series of quadrangular blotches. In large specimens only the upper and 

 lower of the series on the flank can be distinguished. A dark-edged band 

 across the postfrontals, through the eye, over the angle of the mouth. A 

 pair of diverging bands from the parietals to the neck. Anterior spots 

 more or less confluent. Darkening with age until nearly or quite black. 

 East of the Rocky Mountains. 



var. alleghaniensis. 

 Dark brown to lustrous black, mottled with white under the throat. 

 Series of scales 27. Alleghany region and eastward. 



Var. LINDHEIMERII. 



Dark plumbeous, with brown or black blotches on back and flanks. 

 Series of scales 29. Texas. 



Through its varieties this species is so closely related to the following 

 that the separation is a matter of considerable difficulty. It is quite 



