26. DIADOPHIS 653 



Coronella regalis BOULENGER, Cat. Snakes Brit. Mus., Vol. II, 1894, 



p. 208. 

 Diadophis regalis arnyi COPE, Report U. S. Nat. Mus. for 1898, 1900, 



p. 745, fig. 156 (part). 

 Diadophis punctatus DITMARS, Reptile Book, 1907, p. 338 (part). 



Description. Top of head flattened posteriorly, curv- 

 ing slightly downward to the broad, rounded snout. Rostral 

 rather large, much broader than high, bounded behind by 

 internasal, anterior nasal and first labial plates. Plates on 

 top of head are a pair of internasals, a pair of prefrontals, 

 a rather short, broad frontal, two rather narrow supraoculars, 

 and a pair of large, long parietals. Anterior and posterior 

 nasals distinct or united above nostril. One loreal, small 

 and nearly square. Preoculars two, rarely one. Postoculars 

 two. Temporals usually one followed by one, sometimes 

 1 +2. Supralabials normally seven, rarely eight, the fifth 

 and sixth usually largest, the third and fourth normally 

 reaching eye. Infralabials usually eight or nine, the first 

 pair meeting on the midline. Genials in two pairs, the 

 posterior shorter. Scales on body smooth, in 1 7 rows. Anal 

 plate divided. Gastrosteges in the type and Arizonan speci- 

 mens varying in number from 212 to 237. Urosteges in 

 two series of from 58 to 72. 



The body is unicolor, greenish or grayish brown, usually 

 with, but sometimes without, a light transverse collar on 

 the neck. The head is brownish or olive above. The labials 

 are lighter, marked with dark brown or black. The lower 

 surfaces and the outer row of scales are whitish, yellow, 

 orange or red, often with black spots on the head, first row 

 of scales, and gastrosteges. 



Length to anus 470 578 620 



Length of tail 100 79 119 



Distribution. The Sonoran Ring-necked Snake has 



