CROCODILIANS, LIZARDS, AND SNAKES. 675 



tively small. Superior preociilar long; inferior preocular quite small. 

 Supraoculars two, the anterior larger than the superior preocular, and 

 joining the posterior border of the frontonasal by a suture nearly equal 

 to that with the frontal, and separated from the opposite supraocular 

 by a space greater than its own width, but not twice as great. Three 

 small superciliaries; two squamiform postoculars. 



Six inferior labials, which are subequal except the last two, which 

 gradually diminish. A large symphyseal, which is as broad as long. 

 It has two subequal facets on each side for the first labial and the first 

 infralabial, the latter large, and meeting on the middle line. The 

 remaining infralabials of the first series are three in number and are 

 quite narrow. There is a second series of infralabials posterior to the 

 first, consisting of three scales on each side. Those of the first pair 

 are large, and are in contact on the middle line; the second is smaller 

 and subtriangular, and the third is smallest and narrowest in form. 

 The regular squamation begins posterior to these. 



The closed inferior eyelid is covered with three scales, of which the 

 median is the largest. 



Preanal plates five, the median wedge-shaped, with the apex 

 posterior. 



There are two color varieties as follows: 



Var. A, nigra: Upper half of body uniform dark purplish brown; 

 beneath, yellowish white; scales slightly dotted with brown along 

 their lateral edges, especially under the tail. Chin, throat, and across 

 anal slit dusky [A. nigra Fischer). 



Var. B, pulvhra: Lighter with three dark lines; a dorsal and lateral. 

 Sometimes with fainter lines on the adjacent edges of all the rows of 

 scales; the ground color above yellowish gray or ash. 



Specimens from Monterey are uniform purplish brown above, yellow- 

 ish white below. Cat. No. 3188, from San Francisco, is rather lighter, 

 with three narrow dark lines, one on the middle of the back on the adja- 

 cent edges of the two central rows of scales; the other on the adjacent 

 edges of the fifth and sixth rows from the middle. Below this are some 

 less distinct lines on the sides. Smaller specimens from San Diego 

 have, in addition to these, fainter lines along the adjacent edges of 

 every row of scales. 



The characters of this species are tolerably constant. In six speci- 

 mens out of seventeen, 1 find the small preocular absent. The length 

 of the tail in seven specimens varies from four-elevenths to one-third 

 the total length. 



Br. J. G. Fischer' has described a specimen of Var. A as a dis- 

 tinct species under the name of ^4.. nigra. Besides the color charac- 

 ters, he finds it to differ in the shorter tail, and in the longer preanal 

 scales. The tail in his specimen of A. nigra is one third the length, 

 while in his single specimen of A. pulchr a it is two-fifths of the same. 



1 Abhandl. Naturwiss. Ver. Htiiubiirg, IX, 1885 (separate copy, p. 9). 



