REPTILES OF THE PACIFIC COAST. 157 



Coast Range. It is slow of movement and very gentle. 

 When handled, it usually ties itself into a curious ball- 

 like knot — whence its common name — but, like Licha- 

 nura, never tries to defend itself by biting. A female 

 caught in June contains large eggs. 



Family XII. COLUBRIDiE. 



This family contains a large number of snakes in 

 which the belly is covered with a series of large plates; 

 the head-plates are large and more or less regular; the 

 eye is always well developed, but its pupil may be either 

 round or elliptical; there are no rudiments of limbs or 

 pelvis; both jaws are toothed, without poison-fangs 

 near the front of the mouth. 



SYNOPSIS OF GENEEA. 

 a. — Scales smooth. 



b. — Anal j^late divided; nrosteges in two series, 

 c. — Loreal plate absent. 

 d. — Anterior nasal united with internasal, sometimes meeting its 

 mate on top of the snout; rostral prominent, greatly depressed; 



scales in thirteen rows Chilomeniscus. — p. 158. 



d-. — Internasal distinct, anterior nasal not extending onto top of 

 head; rostral slightly prominent, not dejn-essed; scales in fif- 

 teen rows Tantilla. — p. 176. 



c''. — Loreal plate present, 

 e. — Pupil round. 



f. — Rostral not free at edges. 



g. — Fourth infralabial largest; nasal plates usually more or 

 less united; preoculars normally one; temporals 1-2. 

 h. — Snout high, not pointed in profile. 



Contia. — p. 161. 

 h'^ — Snout depressed, jjointed in profile. 



Chionactis. — p. 159. 

 g''. — Fifth (rarely 4th or 6th) infralabial largest; nasals dis- 

 tinct'; preoculars normally two. 



i. — Temporals 1-1; frontal little longer than wide; a nar- 

 row white or yellow collar across nape. 



Diadophis.— p. 164. 



* Rarely united above the nostril in Diadophis. 



