OPHIDIACROTALIDAE CAUDISONA MOLOSSUS. 605 



Caudisona confluenta, COPE, App. Mitchell's Researches, 18G1, 122. COPE, Proc. Acad. 



Nat. Sci. Phila., 1866, 307. ALLEN, Proc. Bost. Soc. Nat. Hist., xvii, 1874, 



307, 309. 

 Crotalus lecontei, HALLOW., Proc. Acad. Nat. Sci. Phila., vi, 1851, 180. Id., Sitgreave's 



Exp. Zufii & Col. Riv., 1853, 139, pi. 18. Id., P. R. R. Rep., x, 1859, 



Williamsou's Route, Reptiles, 18, pi. 3. UEERM., ibid., 25. 

 Caudisona lecontei, COPE, App. Mitchell's Res., 1861, 121. HAYD., Trans. Am. Phil. 



Soc., xii, 1862, 177. 



Caudisona confluenta var. lecontei, COPE, Proc. Acad. Nat. Sci. Phila., 1866, 307. 

 Crotalus cinereous (sic), LECONTE apud HALLOW., Sitgreave's Exp. Zuui & Col. Riv., 



1853, 140 (iu text). 



Examination of more material than that before Professor Cope in 1866 

 has failed to substantiate the distinctions sought to be maintained between 

 confluenta and lecontei ; and as the two forms do not appear to be geographi- 

 cally separated, there may be no necessity for their varietal recognition. 



I have found this common and wide ranging species in various parts 

 of the West, from the British possessions nearly to the Mexican border. At 

 the North it is the only representative of its family, and one extremely 

 abundant in some regions, as those of the Yellowstone, Upper Missouri, and 

 Milk Rivers. In Arizona, where it is associated with several other species, 

 it is not so abundant, nor is it the characteristic form. I found it only in 

 the country about Prescott and on the San Francisco Mountains. 



Specimens. 



No. 510. San Francisco Mountains, July, 1864. 



No. 572. Fort Whipple. 



No. 678. Fort Whipple; length 31 inches; stomach contained an adult 



Sialia mexicana (Bluebird). 

 No. 801. San Francisco Mountains, at an altitude of about 10,000 feet. 



41. Caudisona molossus, (Bd. & Gir.) Cope. 



Crotalus molossus, BD. & GIR., Cat. N. A. Rept., 1853, 10 (New Mexico). BD., IT. S. & 

 Mex. Bound. Surv., ii, pt. ii, 1859, Reptiles, 14, pi. 2. Id., P. R. R. Rep., 

 x, 1859, Reptiles, pi. 24, f. 5 (uo text). COPE, Check-List, 1875, 45. 



Caudisona molossus, COPE, Mitchell's Res., 1861, 124. Id., Proc. Acad. Nat. Sci. Phila., 

 I860, 307, 308. 



Crotalus ornatus, HALLOW, Proc. Acad. Nat. Sci. Phila., vii, 1852, 192. Id., P. R. R. 

 Rep., x, 1859, Parke's Route, Reptiles, 23, pi. 2. 



Muzzle broad; rostral small; scales between superciliaries small, uni- 



