147. With about 24 cross blotches on the back; usually with small side 



blotches; Neb. to Fla. 



J\[atrix sipedon fasaata (Linn.) Southern Banded Water Snake 

 (Tropidonotus fasciata fasdata (Linn.) ) 

 With about 29 cross blotches on the back; sides without small alternating 

 blotches; Fla. 



J\[atrix sipedon pictiventris (Cope) Florida Banded Water 

 Snake 



148. Dorsal blotches or hands larger than the spaces between; belly with if 



regularly placed color markings; Maine to Okla. 



J\latrix sipedon sipedon (Linn.) Common Banded Water Snake 

 Dorsal blotches or bands about equal to the spaces between; belly with 

 color markings arranged in two lengthwise rows; Ind. to S. C. and 

 Ark. 



7\[dtr!x sipedon pleuralis (Cope) Cope's Water Snake 



149 Parietals each about the size of the frontal plate; parietals not joining 

 along the mid-line; with dark alternating spots and blotches on the 

 back and sides; Va. to Fla. and La. 



T^atrix taxispilota (Holbrook) Water Pilot 

 Parietals each considerably larger than the frontal, and joining on the 

 mid'line; usually with dark spots or bands, which are sometimes faint 

 or absent 150. 



150. Eye in contact with one of the upper labials; back and side dark color 



markings joining, forming a diamond pattern (often very faint) ; Ind. 

 to Texas 



J^atrix rhomhifera rhombifera (Hallowell) Diamond'back 

 Water Snake 

 With small scales between the eye and the upper labials; back and sides 

 with alternating dark cross bands 151. 



151. Bellymostlypale;S. C. toFla. 



J^latrix cyclopion floridana GofF Florida Green Water Snake 

 Belly brown posteriorly, with small, light markings; Ind. to La. and Ala. 

 J\[atrix cyclopion cyclopion (D. & B.) Louisiana Green Water 

 Snake 



152. With 21 or more (very rarely 20) rows of scales around the anterior or 



middle of the body (not counting the ventral plates) 153. 



With 19 or less rows of scales around the body 166. 



153. Pupil vertical; with 21 (rarely 20) to 23 rows of scales around the body; 



scales smooth 154. 



Pupil of eye round; with 25 to 35 rows of scales around the body; scales 



smooth or faintly keeled; belly flattened, forming an angle with the 



sides Rat Snakes, Chicken Snakes or Colubers 156. 



154. With a row of brown blotches on the back, each usually with a trans' 



verse, light, central area; usually with smaller blotches on the sides; 

 with nine upper labials; usually with two loreals, one above the other, 

 on each side of the head; back teeth in upper jaw grooved; semi' 

 poisonous; Utah, Ariz;, and Cal. 



Trimorphodon lyrophanes (Cope) Jew's-harp or Lyre Snake 



412 



