. The reptiles of western North America, an account of the species known to inhabit California and Oregon, Washington, Idaho, Utah, Nevada, Arizona, British Columbia, Sonora and Lower California. —Small. Head rather narrow, flat-topped,varying in outline according to position of fangs, etc. Ros-tral as broad as, or broader than, high, in contact with an-terior nasal. Anterior and posterior nasals usually united,at least above nostril. Usually two preoculars and two inter-nasals. Supraocular very large, raised into a horn-like pro-cess, separated from its fellow by from four to six irregularrow
. The reptiles of western North America, an account of the species known to inhabit California and Oregon, Washington, Idaho, Utah, Nevada, Arizona, British Columbia, Sonora and Lower California. —Small. Head rather narrow, flat-topped,varying in outline according to position of fangs, etc. Ros-tral as broad as, or broader than, high, in contact with an-terior nasal. Anterior and posterior nasals usually united,at least above nostril. Usually two preoculars and two inter-nasals. Supraocular very large, raised into a horn-like pro-cess, separated from its fellow by from four to six irregularrows of scales. Eleven to 14 superior and 12 to 14 inferiorlabials, first pair of latter in contact on median line in frontof single pair of genials. Two or three rows of scales be-tween supralabials and eye. Scales in 19 to 25 (usually 21or 23) rowsj feebly keeled except in one to three lower rowson sides, where smooth j those near middle of back withcentral tubercular swellings. Gastrosteges varying from 134to 150. Urosteges 15 to 25, a few sometimes divided. The general color above is gray, often with a yellowish ()c. Papers, Cai,. Ai ai>. Sli., \ oi,. .\ I \ AN I 116. ; fmm a; - wt^ 0: *^ viJi § 5. 1 5 1 i^ 1^^^ ^ 48. CROTALUS 955 or vinaceous tinge, with a series of rather small and indefiniteblotches of grayish or yellowish brown. There usually arefrom 31 to 33 of these blotches between the head and anus,and from three to nine on the tail. Smaller blotches orspots usually are present on the sides and on the tips of thegastrosteges. The supraocular shows an indistinct trans-verse streak. A brown streak runs from the eye to the cor-ner of the mouth. The tail is ash-color with half rings ofbrown, which are much darker near its tip than lower surfaces are yellowish white, sometimes faintlyclouded with brown or gray. Length to anus ..404 415 428 440 450 592 Length of tail to .. 30 38 42 42 31 38 Distribution.—The Sidewinder occupies
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Keywords: ., bookcentury1900, bookdecade1920, booksubject, booksubjectserpents
