39 



the United States." — (Yol. i, p. 484.) As no mention is made as to 

 whether the two feet observed were the anterior or posterior pair, it is 

 possible that the animal here noticed might have been one of the Scin- 

 cidcBj which are also characterized by only one pair of feet, which are 

 the posterior, however, instead of the anterior, as in CJiirotes. Professor 

 Cope does not include it in his "Check-list of North American Batrachia 

 and Eeptilia ", which embraces the reptilian fauna of Lower California. 



CEOTALIDJ]. 



CROTALUS PYRRHUS, Cope [No. 8562]. 



Crotalus pyrrhus, Cope, Check-list, 1875, 33. 



Caudisoma pyrrTia, Cope, Proc. Acad. Nat. Sci. Phila., 1866, 308, 310 — Coues, Wheeler's 

 Geographical and Geological Explorations and Surveys West of the 100th Meri- 

 dian, vol. V, 1875, Zoology, 608, pi. xxii. 



Locality: Angel Island, Gulf of California. This is the first notice 

 of the occurrence of this rare and interesting rattlesnake since the date 

 of its original description by Professor Cope, in 1866, and, as far as I 

 am able to discover, it is the second specimen in existence in any 

 museum.* It is readily distinguishable from all other members of the 

 family, except C. mitchelli, by the presence of scales between the pre- 

 nasals and the rostral ; and from the latter by the greater subdivision of 

 the plates of the head — C. mitchelli having but one loreal, whilst in 

 pyrrhus there are four. 



The general style of coloration is much the same as given in the de- 

 scription and plate (Wheeler's Report), except that the colors in the 

 recent specimen have somewhat faded in alcohol. The ground-color is 

 a pinkish-gray instead of a salmon color. An exact tint, however, can- 

 not be a point of much specific importance in reptiles, as they are known 

 to be susceptible of a certain range of variation in their colors, in order 

 to harmonize with the color of the ground on which they happen to be 

 lying. The markings along the back are reddish-bay. These markings 

 consist of a dorsal row of large hexagonal spots and a lateral row of 

 smaller spots opposite the dorsal patches. On the anterior third of the 

 length of the body, the hexagons are small and regular in outline, and 

 are separated from the lateral spots by a well-defined interspace ; on 

 the middle third, they become more transverse, the lateral angles coa- 



* Since the above was written, the head of a third specimen has been found in tho 

 reserve series of the National Museum. 



