452 REPORT OF NATIONAL MUSEUM, 1893. 



in the Colorado Desert, San Diego County, Cal., near Salton, from 

 Cbrystoval, Ariz., aud other phvces in the GiUi and Cok^rado deserts. 

 It occurs at least as far east as Tempe, where we have specimens from 

 Dr. Wortmau, and I myself have collected it at Vulture, Ariz. 



Eahits. — The Horned Eattlesnake is known locally as the '' side- 

 winder " throughout its range, as Dr. Merriam explains, on account of 

 its peculiar mode of progression : 



When disturbed it moves awaj^ sideways, keeping its broadside towards the 

 observer instead of proceeding in the usual serpentine manner. 



Its feeding habits seems to be similar to those of the Tiger Eattler, as 

 a specimen collected by the Death Valley expedition contained a kan- 

 garoo rat and 2 pocket mice. As it is a small snake It is probably 

 comparatively harmless, though it has a very bad reputation, but there 

 is nothing to indicate that its venom is more virulent than that of the 

 other Eattlesnakes. Dr. Merriam's iiarties brought home 15 specimens 

 and killed a good many more, but no one was bitten. 



As to the breeding habits we have the following observation by Dr. 

 Merriam : 



During the latter part of April aud the earlj- part of May these Rattlesnakes were 

 often found in pairs and were doubtless mating. At such times they lemained out 

 in plain sight over night, instead of retreating 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 accident 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. 



The CiiREEN R.\TTLE8XAKE. 



Crolahis lepidiis,* Kennicott. 



Plate 16. 



1861. — Caudisoua lepUla, Kennicott, Proc. Phila. Acad., xiii, 1861, p. 206.— Cope, 

 in Mitchell's Res. Veu. Rattlesn., p. 124 (1861). — Jploaspis Icjjida, Cope, 

 Proc. Phila. Acad., 1866 p. 310.— Cope, in Wheeler's Surv. W. 100 Mer., v, 

 p. 535 (1875).— Cope, Bull. U. S. Nat. Mus., No. 1, Check-list, p. 33 (1875).— 

 Yarrow, Bull. U. S. Nat. Mus., No. 24, Check-list, pp. 12, 189 (1883).— 

 Cro/«?Hs 7fj>i(ZHS, Cope, Proc. Phila. Acad., 1883, p. 13.— Cope, Proc. U. S. 

 Nat. :\Ius., XIV, 1891, No. 882, p. 692 (1892).— Garman, Rept. Batr. N. Am., 

 I, Ophid., pp. 117, 175 (1883). 



Figures. — None. 



Description.* — The top of the muzzle is covered b^^ 8 smooth scuta; 

 the rostral plate is rather low, and is in contact with the preuasal; there 

 are 2 preoculars and 2 loreals; and but 2 scales separate the orbit from 

 the superior labial scuta. Of the latter there are 12 occipital scales 

 smooth. Scales of body in 23 rows, the 2 external on each side smooth. 

 Gastrosteges (ventrals), 153; urosteges (subcaudals), 27. The rattle 

 consists of 7 segments and a button, and narrows gradually towards 

 the extremity (fig. G8). 



* From the Latiu lepidus, pleasant, nice, smooth. 



