REPTILES OF THE PACIFIC COAST. 



165 



Description. — Top of head flattened posteriorly, but 

 curving slightly downward to broad, rounded snout. 

 Rostral plate large, broader than high, hollowed below, 

 and bounded behind by internasal, anterior nasal, and 

 first labial plates. Plates on top of head, a pair of in- 

 ternasals, a pair of prefrontals, a short, broad frontal 

 between two supraoculars, and a pair of long parietals. 

 Anterior and posterior nasals normally distinct, but 

 rarely united above 

 nostril. Loreal 



small and nearly 

 square. Preoculars 

 and postoculars two 

 each. Temporals 

 one followed by one. Seven (rarely eight) superior and 

 eight (rarely seven) inferior labials, sixth (or seventh) 

 upper and fifth (or fourth) lower largest, third and fourth 

 (rarely fourth and fifth) superior reaching eye, first pair 

 of inferior meeting on median line. Geneials in two 

 pair, anterior very slightly, if at all, larger than poste- 

 rior pair. Scales on body smooth, in fifteen rows. 

 Anal plate divided. Gastrosteges varying in number 

 from one hundred and eighty-two to two hundred and 

 ten. Urosteges in two series of from fifty-three to sev- 

 enty. Tail tapering, ending in a pointed, conical plate. 



The color above is olive, brownish, greenish, bluish, 

 or blackish slate, or gray, minutely reticulated, but 

 without definite markings, except a light col- 

 lar across the neck just behind the head. 

 This collar may be white, yellow, or unicolor 

 with the belly, and is often edged with black 

 or slate. It covers from one and one-half to 

 three transverse rows of scales. The upper 

 part of the head is usually a darker shade of 



