426 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4TH Ser. 
77.—Crotalus molossus Baird and Girard 
Seven specimens of this rattlesnake are in the collection. 
One (No. 17535) was collected, April 4, 1910, at Cave Creek, 
Maricopa County. The others are from the Huachuca Mts., 
in Cochise County. 
No. 17535, Cave Creek, has scale rows 27, gastrosteges 
191, anal entire, urosteges 25, two divided, supralabials 17-18, 
infralabials 17-18, preoculars 2—2, postoculars 3-3, loreal 2-3, 
No. 34735, near Ramsey Canyon, Huachuca Mts., June 29, 
1912, female, has scale rows 27, gastrosteges 189, anal entire, 
urosteges 22, supralabials 17-18, infralabials 16-16, preocu- 
lars 2-2, postoculars 3-3, loreal 1-1. 
No. 34736, head of Ramsey Canyon, July 11, 1912, has 
scale rows 27, gastrosteges 190, anal entire, urosteges 23 two 
divided, supralabials 17-17, infralabials 15-16, preoculars 2-2, 
postoculars 3-3, loreal 1-1. 
No. 34737, Ramsey Canyon, July 30, 1912, has scale rows 
27, gastrosteges 193, anal entire, urosteges 21, supralabials 
17-17, infralabials 18-18, preoculars 2-2, postoculars 3-3, 
loreal 1-1. 
No. 34738, Ramsey Canyon, July, 1912, has scale rows 27, 
gastrosteges 191, anal entire, urosteges 27, supralabials 16-17, 
infralabials 17-18, preocular 2—2, postoculars 3, loreal 1-1. 
No. 34739, Miller Canyon, Huachuca Mts., July 27, 1912, 
female containing seven young, has scale rows 27, gastrosteges 
191, anal entire, urosteges 23, supralabials 17-18, infralabials 
16-18, preoculars 2—2, postoculars 3-3, loreal 1-1. 
No. 34740, Ramsey Canyon, July 28, 1912, has scale rows 
27, gastroteges 194, anal entire, urosteges 20 two divided, 
supralabials 18-18, infralabials 17-18, preoculars 2-2, post- 
oculars 3-3, loreal 1-1. 
78.—Crotalus atrox Baird and Girard 
The collection includes one specimen (No. 33656) from 
Yuma, Sept. 14, 1912) six (Nos. 17532; 17533) 17334), Wases 
17537, 17538) from Cave Creek, Maricopa County, April 10- 
May 15, 1910, and ten from the vicinity of Tucson, April 11— 
August 23, 1912. These all show the typical coloration. 
Their scale characters are shown in the following table: 
