OPHIDIA— CROTALIDAE— CAUD1SONA CERASTES. (309 



teen, the first and second margining a plate, which meets its fellow in front 

 of the geneials, and is in other species a continuation of the first. Gastro- 

 steges, 178; urosteges, 84; joints of rattle, 9. The general tint of this 

 species is a bright salmon-red ; the scales of the inferior rows pnnctnlate 

 with brown. 



Nasal plates distinct: muzzle with small plates or numerous scales 

 above [as in cerastes and mitchelli]. Upper margin of canthus rostralis 

 with small scales like the others. Prenasal separated from rostral by scales; 

 superciliary not prolonged. Rostral broad as long-; head very obtuse, 

 rounded. Scales 25 rows; 7 between superciliaries, 3 below orbit; labials, 

 14; 2 very small preorbitals and 4 loreals. Pale-vermillion varied with 

 yellow on the sides of the belly, with numerous large reddish-bav hexagons, 

 which become transverse bands on posterior two-thirds of length ; yellow 

 below. Rattle subacuminate. 



This species is one of the most handsomely colored of the genus. Its 

 affinities are with the C. mitchelli, < 'ope; lint it exhibits an even higher degree 

 of subdivision of the head shields. — {Cope, descr. orig.) 



A single specimen of this richly colored species was procured at Canon 

 Prieto, a locality near Fort Whipple. It is not in the best order, as it was 

 procured under the untoward circumstances of a hasty retreat from hostile 

 Indians. The species is probably rare, as I never met with a second exam- 

 ple, while that one procured was regarded as a curiosity by the numerous 

 persons who came to see a "red rattlesnake". 



4(5. Caudisona (^Echmophrys) cerastes, (Hallow.). 



Crotalvs cerastes, Hallow., Proc. Acad. Nat. Sci. Phila., 1«54, 95. —Id.. V. R. R. Rep., 

 x, 1S59, Williamson's Route, Reptiles, 17. — Heerji., ibid., -4. — Bd., V. S. 

 & Mex. Bound. Surv., ii, pt. li. 1859, Reptiles, 14, pi. 3. — Cope, Check-List, 

 1875, 33. 



Caudisona cerastes, Cope, Proc. Acad. Nat. Sci. Phila., 18GG, p. — . 



Mchmoplvrys cerastes, Coues. 



Head small, with rounded angles; nose depressed, obtuse; rostral 



as broad as high ; nostril in middle of a single large plate ; lateral edge of 



superciliary plate elongated into a horn-like process over the eye. Two 



rows of scales between the suborbital series and the labials ; superior labials 

 39 z 



