Hat, 1898.] REPTILES OF THE DEATH VALLEY EXPEDITION. 217 



The locality is certainly indefinite, to say the least, and a more favor- 

 able expression can hardly be used about l Colorado River, Colorado,' 

 for specimen No. 482, which was probably collected near Fort Yuma, 

 California, and certainly not in the State of Colorado, as the catalogue 

 referred to would seem to indicate. 



It is refreshing to turn from these unreliable and confusing state- 

 ments to the list of exact localities furnished below for each individual 

 specimen taken, and nothing will better illustrate the value of the work 

 clone by the Death Valley Expedition than the parallel just drawn. 



[The horned rattlesnake or 'sidewinder,' as it is locally known 

 throughout the region it inhabits, is the characteristic snake of -the 

 Lower Sonoran deserts of the Great Basin, from southern California 

 easterly across southern Nevada to Arizona and southwestern Utah. 

 It inhabits the open deserts, while its congener of the same region 

 (G. tigris) lives in the desert ranges. Its local name is derived from its 

 peculiar mode of progression : when disturbed it moves away sideways, 

 keeping its broadside toward the observer instead of proceeding in 

 the usual serpentine manner. Its bite is said to be fatal, which is 

 probably not the case under ordinary circumstances. A large number 

 were secured by the expedition and many others were killed, but no 

 one was bitten by it. It was found on both sides of Pilot Knob in the 

 Mohave Desert (April 5 and 6) in Pahrump Valley, where four were 

 caught in a space of a mile and half (April 28 and 29); in Vegas Valley 

 (May 1); in Vegas Wash (May 3); in Indian Spring Valley (May 29), 

 where one was shot containing a kangaroo rat (Dipodomys) and two 

 pocket mice (Perognathus); in the Amargosa Desert (May 31), and 

 in Sarcobatus Flat (June 2). It was common in the valley of the 

 Virgin and Lower Muddy (May 6 and 7), and was said to inhabit Pah- 

 ranagat Valley, though we did not find it there. 



During the latter part of April and the early part of May these rat- 

 tlesnakes were often found in pairs and were doubtless mating. At 

 such times they remained out in plain sight over night instead of re- 

 treating to holes or shelter under desert brush, and on two occasions 

 they were found by us on cold mornings so early that they were too 

 chilled to move until considerably disturbed. I stepped on one of these 

 by accideut as it lay in a compact coil with its head in the center, but 

 it was held so firmly by my weight that it was unable to strike. A 

 moment before, I had killed its mate. I killed three on the mesa east 

 of St. Joe, in the valley of the Muddy, in eastern Nevada, May 7. — 

 C. H. M.j 



