13. COLUBRID^ 



posterior nasals distinct. Loreals three, true loreal one, 

 short and high ; one or two small subloreals. Two or three 

 preoculars, two or three postoculars and one or two subocu- 

 lars complete the orbital ring. Temporals two, three, or 

 four followed by about three. Supralabials six, two or 

 three posterior largest, none reaching eye. Infralabials 

 nine, first and fifth largest, first pair meeting on median 

 line. Genials in one pair, or posterior pair small. Scales 

 on body in 19 rows, everywhere smooth. Anal plate not 

 divided. Gastrosteges varying in number from 161 to 183. 

 Urosteges in two series of from 26 to 35. 



The color above is whitish with from 23 to 48 chocolate- 

 brown blotches between the head and the tip of the tail. 

 These blotches are more or less irregular in size and shape 

 but their borders usually are more or less concave in front 

 and behind. The blotches are paler centrally, where the 

 brown color is merely sprinkled over the white ground. 

 Along the sides are smaller brown spots, two or three scales 

 in diameter, in a more or less double series, usually alternat- 

 ing with the dorsal blotches. A broad dark line crosses the 

 head on the prefrontals and is continued down and back 

 through the eye to a point above the angle of the mouth. 

 There are a few irregular spots on the posterior portion of 

 the frontal, the parietals, the anterior portion of the neck, 

 and some of the supralabials. The lower surfaces are white, 

 without markings. 



Length to anus 272 321 363 



Length of tail 28 29 40 



Distribution. — Only five specimens of this snake have 

 been found. The original one was brought from the "upper 

 part of Lower California" by Mr. William M. Gabb. Mr. 

 Belding and Mr. Slevin each secured one at La Paz near 

 the southern end of the peninsula. The fourth specimen 



