WATER SNAKE. 683 



of Dr. Kirtland, as a slight token of the respect due him to whose enthu- 

 siastic and untiring devotion to Science the West owes so much, I would 

 also make some expressioa of my personal gratitude to the honored 

 teacher, whose kind encouragement and instruction led me to study Na- 

 ture, by dedicating to him his pupil's first contribution to Science." 



Genus TROPIDONOTUS. Kuhl. 



Body thick and stont ; size large; cephalic plates nonual ; anteoibitals one, sometimes 

 two ; postorbitals three, rarely two ; labials and inframaxillaries large ; nasals two ; 

 loral present; prefrontals two; dorsal scales in '23 -29 rows, carinated; gastrosteges 

 130-155 ; arosteges 65-85 all divided ; postabdominal scntella bifid ; general color three 

 to five series of dark blotches npon a lighter ground; habits aquatic ;'TeprodDction 

 ovoviviparous. 



Dorsal scales in 23, rarely 25 rows. a. 



Dorsal scales in 25 rows ; upper labials 9, lower 11 ; extralimital. . T. woodhotjsii. 



Dorsal scales in 27 rows. . . • T. rhombipbr. 



Dorsal scales in 29 rows ; extralimital, North Carolina to Georgia. . T. taxispilota. 

 a. Abdomen usually spotted with dark. b. 

 a. Abdomen nnicolor. o. 



J. Gastrosteges 137-145 T. sipedon. 



6. Gastrosteges 128-133 T. PASCiAins. 



o. Anteorbitals one or two. . . . . . T. krtthrogaster. 



Teopidongtos sipedon Linnaeus. 



fVater Snake or VFater Adder. 



Coluber sipedon, Linn^us, Shaw, Mbrrbm, Harlan, Kirtland, Storbr. 

 Tropidonotus aipedon, Holbrook, DeKat, Dumeril and Bibron, Verrill. 

 Coluber poedogaater, Wibd. 



Regina grahamii Baird and Girard. 



Oraliam's Snake. 



Tropidonotus grahami, Gunther, Cope, Jordan. 

 Eegina grahamii, Baird and Girard. 



General color above brown, with a light vertebral line margined with black ; lateral line 

 yellow, with a black margin siiuated upon the first, second, and third rows of scales ; 

 abdomen yellowish, without spots; vertical plates neavly pentagonal, with the sides notched 

 it little behind the center ; anteorbitals two ; nasals one; upper labials seven, lower eight; 

 postorbitals above the line of union of the fourth and fifth upper labials ; inframaxillaries 

 reaching to the anterior end of the seventh lower labials; dorsal scales in 19 rows; 

 gastrosteges 160-162; nrosteges 57. Length, 20^ inches; head, f inch; tail, 4 inches; 

 transverse diameter of head, 5-16 inch ; of neck, J inch ; circumference of body, IJ inch. 



Habitat, Mississippi Valley from Western Mexico, Texas and Louisiana, to Illinois and 

 Michigan. 



Although I have no record of this species having been observed in the State, its 

 range is sach as to render its oconrrence in Ohio probable. 



