POISONOUS SNAKES OF NORTH AMERICA. 403 



between these and tlie posterior nasal. Labial not forming part of the 

 orbit, bnt seoarated by the four post and suborbitals. Labials not so 

 largely developed; S above, third and fourth largest; 9 below. 



Above light hazel brown, rather brighter on the top of the head, and 

 everywhere minutely mottled with very fine, dark points. On each side 

 is a series of 15 to 20 darker chestnut-colored blotches resting on the 

 abdominal scutelhe jventrals. or gastroteges], and suddeidy contracting 

 about the middle of the side, so as somewhat to resemble an inverted Y- 

 These bh:>t(;hes extend to the vertebral line, where they may be trun- 

 cated or end in a rounded apex. Generally, those of opposite sides 

 alternate with each other, but frequently they are confluent above, form- 

 ing continuous bands. They are so disposed that the intervals between 

 the successive blotches are pretty much of the same shape and size, 

 though inverted. The centers of the blotches are lighter; in some cases 



Fig. 41. . Fig. 42. 



HEAD OK COPl'ERHEAD, SHOWN FROM TOP AND SIDE. 



( After Bainl. ) 



SO much so as greatly to increase the yshaped resemblance. Color 

 beneath dull yellowish, with a series of distinct large, dark blotches, 35 

 to 45 in number, on each side. Chin and throat unspotted. Sides of 

 head cieam color tlie line of demarcation very distinct; this i)asses 

 along the upi)er edge of head, in front of the eyf, and involving the 

 lower tliree-fouitlis of the orbit, intersects the middle of the second 

 postorbital plate (counting from above), and extends along the tirst 

 row above the labials to the posterior edge of the last labial. The line 

 then comes back through the middle of the lower labial range, where it 

 is marked by a narrow black line, llostral of the same color. A small 

 areolated dark si)ot near the inner edge of each occipital [i)arietalj plate. 



Number of gastrosteges, 150 to 154; urosteges, undivided, 31 to 48; 

 divided, to 18 pairs. 



Fresh colors of Aglcistrodon contortrlr (young) — No. 192(31; District of 

 Columbia, Government Insane Asylum grounds; Dr. J. W. Blackburn, 

 collector, Se[)tember 10, 1892 (died in captivity October 31, 1892). 

 Ground color above dull vinaceous-cinnamon (Rob. Ridgway, Nomen- 

 clator of Colors, pi. iv, lig. 15), head darker, drab (iti, 18), marked with 

 tawny on the temples; dark markings, dark Front's brown (iii, 10), 

 gradually fading into drab on the sides; tip of tail for the extent of 

 about 20 mm., both above and below, bright olive-yellow (vi, 1<!), the 

 general ground color gradually fading into it at about 25 mm. from 

 the tip; ground color below ecru-drab (ill, 21), dark markings seal- 

 biown (III, 1); lii>s i>ale ecru drab, the dark edge externally shaded 

 with tawny-olive. Iris silvery vinaceous-cinnamon. 



