Reptiles (i)irl AmphihiiOix of Illinois. 'l^'-\ 



12 ( 8). One nasal. 



18 (18). Nasal grooved below nostril Regina. 



14 ( 7). Loreal absent Storeria. 



IT) ( 1). Dorsal scales smooth. 



16 (28). A.nteorbitals present. Loreal not reaching orbit. 



17 (VX). One nasal, not grooved below nostril. (yolor 



green Cyclophis. 



15 (18). One nasal plate, not grooved below nostril. Color 



green Phyllophilophls. 



19 (17). Two nasal plates. 



20 (24). Anal divided. 



21 (2-")). Upper anteorbital large, lower small. No pale 



ring on neck (Joi.uber. 



22 ( 8). Rostral wedged between internasals. Two pre- 



frontals PiTYOPHIS. 



28 (11). Dorsal scales feebly carinated. Size large. 



Elaphis. 



24 (20). Anal entire Ophibolus. 



25 (21). Anteorbitals about equal in size. A pale ring at 



base of head Diadophis. 



26 ( U). Rostral plow-shaped. With an azygos plate. 



Heterodon. 



27 (10). No anteorbitals. Loreal reaching the orbit. 



Haldea. 



28 (16). No anteorbitals. Loreal reaching the orbit. 



29 (31). One nasal. 



80 (82). Nasal grooved below nostril. Dorsal rows 19-21. 



* Hydrops. 



81 (29). Two nasals. Dorsal rows 15 or 17 Virginia. 



32 (80). Nasal not grooved below nostril. Dorsal rows 13. 



Carphophis. 



EUTAINIA, Bl). AND GiR. 



Hd. and VAX., Cat. X. A. Kept. Pt. 1., 1853, p. 24. 



Dorsal scales carinated, in from nineteen to twenty-one 

 rows. Rostral normal. Two internasals. Two prefrontals. 

 Two nasals, the nostril between. Loreal present. One anteor- 

 bital. Three postorbitals. Anal entire. Body moderately 



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