334 PROCEEDINGS OF THE ACADEMY OF 



with black, somewhat as in E. Marciana , except the seventh plate, which 

 in the former is heavily bordered with black on both edges ; in the latter, 

 slightly upon the anterior edge alone. There is a vertical light patch at the 

 angle of the mouth crossing the posterior upper labial, and confluent with the 

 white of the neck, and not distinct and crescent-shaped as in Marciana. 

 Behind the occipital plates is a very large double black blotch. Behind this 

 there are three or four perfect square blotches extending quite from the dorsal 

 to the lateral stripe, each three scales in length, and separated by intervals 

 of about two scales wide. Behind these the general pattern of spots is seen ; 

 it consists of two series of large oblong rhomboidal alternating spots, each 

 about four scales long, and somewhat confluent with each other at the adja- 

 cent corners, giving the appearance of a zigzag line upon each side. On the 

 first and second dorsal rows is a third series of very distinct black spots, eactt 

 on parts of three scales, and the extremities of two abdominal scutes. The 

 intervening spaces of greenish white ground color are equal in width to the 

 spots. 



No. 930, Rinconada Coahuila, Mexico, 179 ; 90, 19, 24|, 6. Lieut. Couch. 



Durango, Lieut. Couch. 



Gila River. Dr, Webb. 



Other specimens have the dorsal stripe on a single row of scales, and the 

 lateral stripe has its upper border regular and distinct, without interruption 

 from the middle series of spots, the lower edges of which reach only the up- 

 per edge of the third row instead of the lower edge as in the specimen above 

 described. Instead of the distinct spots upon the first and second rows in 

 that specimen, they are here broken up into black borders of three approxi- 

 mated scales. In the only large specimen of this variety, the keels of the 

 first dorsal row are not parallel to those of the rows above, being directed 

 obliquely downward and backward, so that the posterior end of one ke^l falls 

 below the anterior end of the next succeeding, instead of forming a continu- 

 ous line. The nose of this specimen is also more pointed than in the typical 

 one. 



REGINA Baird & Girard. 

 R. valida Kennicott. 



Spec. char. Body stout for the genus ; head large, short but high ; broad 

 posteriorly. Snoui elongated, narrow and pointed. Rostral as high as broad, 

 subpentagonal, the apex pointed. Vertical very narrow, obtusely pointed 

 posteriorly : occipitals small. Nineteen rows of scales, all carinated ; the ex- 

 terior very feebly. Light brownish ash above, with faint black markings 

 upon the bases of the scales of the first, fourth and eighth rows of scales. 

 Abdomen entirely uniform yellowish. 



Descr. The body is stout for the genus, with the tail rather short. The 

 head is very large and proportionally stout. It is very broad and high pos- 

 teriorly, and tapers regularly to the snout, which is rather narrow, elongated, 

 and pointed. Crown flattened as in other species of the genus. Snout ele- 

 vated, rostral plate as high as wide, subpentagonal, and with the elongated 

 apex pointed. Loral nearly as high as long. Anterior frontals triangular, 

 elongated. Vertical very narrow, not widening anteriorly, the posterior point 

 very obtuse and scarcely triangular. Superciliaries proportionally wide, and 

 occipitals small. There is one rather large anteorbital, and two large postor- 

 bitals on one side, and three on the other, (which may possibly be the normal 

 number). Upper labials large, sixth and. seventh largest, eighth (the last) 

 smaller. Inferior labials ten, sixth longest. 



The dorsal rows are nineteen, all carinated, the outer row very slightly. 

 The scales of the first row are much the largest ; all the rest about equal. 



The color above is entirely uniform light brownish ash, (clay color beneath 

 the epidermis), with about every alternate scale on the fourth and fifth rows. 



[A 



ug. 



