1922] Schmidt, Amphibians and Reptiles of Lower California 699 



caudal rings in the females, five to seven in the males. The tail is rela- 

 tively much shorter in the female specimens, .05 of the total length, .07 

 to .08 in the males. The largest specimen (A. M. N. H. No. 5645, d" ) 

 measures 1015 mm., tail 88 mm. 



As Crotalus atrox certainty enters the peninsula of Lower California 

 at the north, and as the differences on which lucasensis is based are slight, 

 the use of a trinomial seems warranted. 



Three specimens in the Biological Survey collection from Cape San 

 Lucas (U. S. N. M. No. 37567), La Laguna (37568), and Santa Anita 

 (37569). 



Crotalus atrox elegans, new subspecies 



Diagnsotic Characters. — Characters of Crotalus atrox, from which it is distin- 

 guished by the higher number of ventral plates and the reddish brown color; distin- 

 guished from C. atrox lucasensis by the incompleteness laterally of the light outlines of 

 the dorsal rhombs, and by the higher number of ventral plates. 



Range. — Angel de la Guardia Island, Gulf of California. 



Type.— U. S. N. M. No. 64452; <?; Angel de la Guardia Island, Gulf of Cali- 

 fornia; April 10, 1911 ; Albatross Expedition. 



Description of Type. — Head subtriangular, covered with numerous small 

 scales; ten scales in a line, between the large supraoculars; rostral higher than 

 wide; two large preoculars on each side, of which the lower enters the loreal pit; 

 two superior loreals on each side; four or five scales from the eye to the upper labials; 

 upper labials 16-17, lower labials 18, of Avhich only three on each side are in contact 

 with the chin shields; dorsal scales, 35-27-21 ; ventrals, 197; subcaudals, 26; total 

 length, 920 mm.; tail, 60 mm. 



General color light reddish brown, marked dorsally with a series of slightly darker 

 ihombs, which are bordered by narrow light lines; rhombs lighter at the center; 

 these rhombic markings become difficult to distinguish on the anterior fourth of the 

 body, but the light scales of their borders can be distinguished on the vertebral line; 

 on the posterior fourth of the body, the light lines become entirely faded, the slightly 

 darker markings forming broad transverse bands. Tail yellow, with five black rings, 

 incomplete ventrally; venter uniform pale yellow; an indistinct light line from the 

 preoculars to the middle of the labial border, and a very faint line from the posterior 

 corner of the eye to the sixteenth upper labial. 



Notes on Paratypes. — The two female specimens from Angel de la Guardia 

 (A. M. N. H. Nos. 5231 and 5586) have respectively 200 and 199 ventrals, and 21 and 

 20 subcaudals. The dorsal scale count is 31-27-21 . The ground color is more gray- 

 ish but shows a trace of the reddish tinge which is better marked in the type. The 

 dorsal light lines enclosing the rhombs are incomplete at the sides. 



I have described this form as a subspecies of C. atrox in order to 

 indicate its obvious relations. The higher ventral scale count is nearly 

 reached in a specimen of C. atrox lucasensis which has 195 ventrals; 

 the average for the two forms is evidently quite different, but the ex- 

 tremes probably overlap. Additional material is required to determine 

 whether it is to be considered an off-shoot of lucasensis or of atrox atrox. 



