1901.] NATURAL SCIENCES OF PIIILADELriilA. 103 



scales ill 27-20 rows, as in most of the species the first and second 

 rows are faintly keeled or smooth; ventrals 169-178; subcaudals 

 25-32. The largest specimen I have seen, measured 1,910 mm. 

 and came from St. Simon's Island, Ga. It was formerly in pos- 

 session of the Zoological Society. There is little doul)t that the 

 species reaches 2, 200 mm. or more. 



Yellowish gray above, with lozenge-shaped dorsal lilotches 

 sharply defined, blackish, with centres of the l)ody color, and 

 separated by oblique yellow lines crossing each other on the Ijack; 

 on the sides in the triangular open spaces which alternate with the 

 lozenges, there is a black spot; other indistinct markings some- 

 times appear on the sides; posteriorly the colors are somewhat 

 darker and the lozenges take the shape of cross-bauds, which form 

 not very well-defined rings ou the tail, but the colors there are not 

 sharply contrasted; belly yellowish white, clouded with brown 

 toward the sides. There is a wide dark oblique streak from below 

 the eye to the labials, bordered in front and behind by a light one; 

 two light bars from the loreal pit to labials, and another in front 

 of the nostril. 



Hab. — North Carolina and Florida; west to Louisiana and prob- 

 ably eastern Texas. 



Crotalus atrox B. and G. 

 I. c, 5. 

 The western representative of the diamond rattlesnake is very 

 like it in appearance, but may always be distinguished by the 

 absence of the light vertical line in front of the nostril, by the 

 absence of sharply defined angles to the dorsal spots and by the 

 strongly contrasted black half rings on the tail. A rai*e form, 

 known only from southern California, is retained as a subspecies. 



Color grayish or brown; markings distinct, . . 1. C. a. atrox. 

 Color red ; markings not very distinct, . . . 2. C. a. ruber. 



Crotalus atrox atrox B. and G. 



I. c, 5; C. adamanteus a.trox and C. a. sautulatus Cope., I. c, 690, 

 aud Rep. Xat. Mus., 11G4, 1159; C. sciitnlatus and C. confluentus 

 (part) BouL, I. c, III, 575, 576 ; C. atrox Stej., I. c, 436. 



Size rather less than adamanteus, but form and scutellatiou very 

 similar; the supraoculars are sometimes but not always bordered 

 internally by a row of enlarged scales; rows of scales between 

 supraoculars often 4, but sometimes •! or (>; 3-4 scales between 



