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. COLUBRID^. 



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 GENERA, 

 a. Scales smooth. 



b. Anal plate divided; urosteges 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-. Interuasal distinct, anterior nasal not extending onto top of 

 head; rostral slightly prominent, not depressed; scales in fif- 

 teen rows Tantilla. p. 176. 



c 2 . 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 2 . Snout depressed, pointed 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 j^ellow collar across nape. 



Diadophis. p. 164. 



* Rarely united above the nostril in Diadophit. 



