846 13. COLUBRIDM 



faint occipital spot. The sides of the head are dusky yel- 

 lowish, with vertical blackish marginings to the supralabials. 



Length to anus 304 382 440 500 670 870 



Length of tail 93 109 120 143 180 275 



Variation. The loreal in seventy-five specimens is 1 1 

 in all. Preoculars 2 2 in thirty-one, or 42%; 1 1 in 

 twenty-seven, or 36 %; 2 1 in thirteen, or 18%; 3 3 in 

 two, or 3%; and 2 3 in one, or 1%. Postoculars 3 3 in 

 sixty-six, or 92%; 3 4- in three, or 4%; 4 4- in two, or 

 3%; and 3 2 in one, or 1%. Temporals 1+2 1+2 in 

 forty-two, or 56%; 1+2 1+3 in twenty-one, or 28%; 

 1+3 1+3 in twelve, or 16%. The supralabials are 8 8 

 in all except one specimen which has 8 9. The infralabials 

 are 10 10 in sixty-nine, or 92%; 10 9 in three, or 4%; 

 9 9 in two, or 3 % ; and 1 1 1 in one, or 1 %. The scale- 

 rows are 21 21 17 in sixty-two, or 83%; 21 19 17 

 in eleven, or 15%; 192117 in one, or 1%; and 19 

 19 17 in one, or 1 %. The gastrosteges vary from 156 to 

 173, males having from 163 to 173, females from 156 to 

 171; the average in thirty-seven males is 168.1, in thirty- 

 four females, 162.6. The urosteges vary from 67 to 88, 

 males having from 69 to 88, females from 67 to 82; the 

 average in twenty-five males is 8 1 .2, in twenty-one females, 

 73.1. 



Distribution. This subspecies is the common water- 

 snake of southern California west of the deserts. Where 

 streams run from the western mountains down onto the 

 desert this snake may follow them for some distance, as, 

 to Victorville on the Mohave River, and Palm Canyon at 

 the eastern base of the San Jacinto Mountains. It ranges 

 at least from sea level to an altitude of 8,000 feet. The 

 most northern locality from which we have seen a typical 



