Title: Bulletin
Identifier: bulletin2819611963illi (find matches)
Year: 1918 (1910s)
Authors: Illinois. Natural History Survey Division
Subjects: Natural history; Natural history
Publisher: Urbana, State of Illinois, Dept. of Registration and Education, Natural History Survey Division
Contributing Library: University of Illinois Urbana-Champaign
Digitizing Sponsor: University of Illinois Urbana-Champaign

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November, 1961 Smith: Amphibians and Reptiles of Illinois 189
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Fig. 182.—An adult Hctcrodon platyrliinos from Lee County, Illinois. The groundcolor may be tan, gray, rusty red; the markings, dark gray, brown, or black. Frequent specimens are unicolor olive or black; others, dark with vestiges of the blotched pattern. Table 52.—Sexual variation in Illinois Heterodon platyrhinos. Figures in parentheses are numbers of specimens. Characteristic Ventrals Caudals Body blotches Tail rings Tail length as percentage of total length Males (32) Range Mean 122-134 44-57 19-29 7-11 15.7-20.8 Females (22) Range Mean 128.2 48.7 22.6 8.9 17.9 134-147 38-48 21-29 6-10 12.7-16.6 141.6 42.6 24.9 7.9 14.4 No geographic variation in scutellation in Illinois Heterodon platyrhinos has been dis- cerned. Of 54 specimens examined, 3.7 per cent have 24 anterior rows of scales, 67 per cent have 25, 18 per cent have 26, and 11 per cent have 27; 6 per cent have 23 scale rows at mid-body, 4 per cent have 24, 83 per cent have 25, 5 per cent have 26, and 2 per cent have 27; 6 per cent have 18 posterior scale rows, 85 per cent have 19, 2 per cent have 20, and 7 per cent have 21. Supra- labials are 7 + 8 in 7 per cent, 8 -h 8 in 87 per cent, and 8 + 9 in 6 per cent. Infra- labials are 8 -j- 9 in 2 per cent, 9 + 9 in 6 per cent, 9 + 10 in 11 per cent, 10 + 10 in 60 per cent, 9+11 in 2 per cent, 10 -f 11 in 6 per cent, 11 + 11 in 11 per cent, and 11 + 12 in 2 per cent. Other variation is summarized in table 53. The average number of body blotches tends to be higher in snakes from northern localities than In those from other parts of the state. Habits.—The eastern hcgnose snake Is similar in habits to Heterodon nasirus. When encountered In the field it spreads its head and neck widely and hisses; If this bluff fails, it rolls over on Its back and "plays

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