POISONOUS SNAKES OF NORTH AMERICA. 429 



the yellow scales external to the blotches are of a liiihter color than 

 the lest. 



Niiiiiber of veiitrals (<;astro.steges), KiO; of subcaudals (iirostejies), 25', 

 dorsal scale rows, 23. 



T« tal length, 42 inches; tail, o inches. 



Variation. — There is considerable individual variation, both in 

 S(;ut('llation of the bead and the ground color of the bodJ^ 



The variation in the scutellation on top of the bead is especially 

 marked with regard to the prefrontals and the scales covering the can- 

 thus rostralis. Normally the large plates consist of 2 iiiternasals, 2 

 supraoculars, and between these, on ea(;h side, a large shield, the pre- 

 frontals usually being small scales like those covering the rest of the 

 head. In two of our specimens, however (Nos. 277 and 12748), there 

 are a pair of large prefrontals following the internasals, while in Nos. 

 277 and 248 there are 2 scutes between the internasal and the supra- 

 ocular on each side instead of 1. 



The ground color varies greatly from light yellowish and light red- 

 dish gray through brown to almost black in some instances. In old 

 specimens the tail is generally uniform black, but in the young ones it 

 IS l)anded light and black. In many specimens from localities in the 

 Alleghany Mountains, with a moist (diniale, this black of the tail and 

 sometimes even of the entire posterior half of the body is often of a deep 

 velvety gloss. 



In the majority of the Western specimens there is a broad, ill defined, 

 but very distinct, ochraceous band running down the center of the 

 back. Most of them also have the postocular dark baiul darker and 

 better delined than Eastern si)ecimens; but 1 have been unable, with 

 iny material, to draw any line sufficiently constant. 



(ieographivul (listributiou. — In former times the Banded Rattlesnake, 

 or "Timber llattlesnake," as it is often called in regions where other 

 spe( ies also occur, was commonly distributed in suitable localities all 

 over the eastern United States, except the peninsula of Florida, as far 

 west as the snbarid portion of the Great Plains, but they have now 

 become exterminated or nearly so, in many localities, having been 

 driven back to the wilderness by the advancing cultivation of the 

 country. 



Prof. Verrill (Proc. Boston Soc. Nat. Hist., ix, 1863, p. 197), speaking 

 of the rei>tiles of Norway, Me., states that it is rare, and only found in 

 Albany and Paymond; he had never detected it east of the Androscog- 

 gin River. In Massachusetts, according to Allen (Proc. Bostor^ Soc. 

 Nat. Hist., XTi, 1808, p. 179), it is not unfrequent on JNIount Tom, and 

 occasionally killed on rocky hills in several of the towns near or adjoin- 

 ing Springtield; it also occurs at a few similar localities in the eastern 

 ]>art Of" the State. 



In ISSG Prof. A. S. I'ackard had an article in the Ameri<'an Natu- 

 ralist on " The Rattlesnake in New England" (Vol. xx, pp. 730-737) from 

 which 1 (piote the following: 



