1196 



REPORT OF NATIONAL MUSEUM, 1898. 



row of large spots of a niabogaiiy red, which are quadrate on the 

 auterior part of the body, become transversely hexagonal, then len- 

 ticular, and finally form cro^s bauds. There are thirty-two snch spots 

 on the body, and six annuli on the tail, which are interrupted by the 

 urosteges below. These are of the same color as those of the back, 

 except the last three, which are nearly black. Inferior surfaces light 

 salmon color. The ends of the gastrosteges are marked with alternate 

 blotches of yellow and mahogany, each covering tlie extremity of one or 

 two scuta. There are no distinct color marks on the head, but the lips 

 are lighter. Formula: 



Cat.No.6606; rowsof scales, 23; upper labials, 15; gastrosteges, 174 ; urosteges, 26 ; 

 total length, 770 mm. ; tail, 87 mm. ; rattle, 43 mm. 



This species was dedicated to Dr. S. Weir Mitchell, of Philadelphia, 

 author of the well known researches on the venom of the rattlesnake, 

 the Heloderma, etc. 



Crotalus mitchellii Cope. 



Besides the above specimens, Mr. Van Denburgh records specimens 

 from the following localities in Lower California: In the museum of the 

 California Academy of Sciences, Santa Margarita Island, one; Las Hue- 

 vitas, one; Sierra El Taste, one; San Jos6 del Cabo, seven; total, ten 

 specimens. 



CROTALUS CERASTES Hallowell. 



Crotalus cerastes Hallowell, Proc. Acad. Nat. Sci. Phila., 1854, p. 95; U. S. 

 Pac. R. R. Expl. Report, Williamson's Rep. Re])tile8, 1859, p. 17.— Baird, 

 U. S. and Mex. Bound. Surv. Reptiles, 1859, p. 14. — Cope, Check-list N. Araer. 

 Batr. Rept., 1875, p. 33.— Stejnegkr, Report U.S. Nat. Mas. for 1893,1895, 

 p. 450, pi. XV.— Boulenger, Cat. Snakes Brit. Mus., Ill, 1896, p. 583. 



Crotalus (jEchmophrys) cerastes Coues, Report U. S. Geog. Surv. W. of 100th 

 Mer,, 1875, p. 609. 



Size small and medium. Head wide, the muzzle short and obtuse 

 and with indistinct canthus rostralis. Rostral plate in immediate con- 

 tact with the prenasal, low in form, or wider than high. Postnasal 



