214 VERTEBRATE ANIMALS OF THE UNITED STATES 



scales in from 19 to 33 rows; ventrals about 140; colors brown or black: 

 many species in North America and Eurasia, all viviparous and semi- 

 aquatic, living along the borders of streams or ponds and feeding on 

 frogs, fish and other cold blooded animals. 



Key to the United States Species of Natrix 



ai Body striped longitudinally. 



bi Scales in 19 rows; upper labials 7. 

 Ci Abdomen with 2 broken stripes. 



di Ventrolateral light stripes; eastern States N. septemvittata. 



d2 No ventrolateral Hght stripes; southeastern States. A\ rigida. 



C2 Abdomen plain or with a central black stripe N. grahamii. 



bo Scales in 21 rows; Gulf States A. clarkii. 



a 2 Body with transverse bands or spots. 



bi Scales in 19 rows; central States A. kirtlandii. 



b2 Scales in 21 rows; Florida A. comprcssicaiida. 



bs Scales in 23 to 25 rows. 



Ci A light line from eye to angle of mouth; ventrals 123 



to 135 A. fasciata. 



C2 No such Hght line. 



di Half-moon shaped spot on belly; ventrals 135 to 

 145; pattern of bands anteriorly and alternating 



blotches posteriorly A. sipcdoii. 



do Belly uniform yellow or red; adults uniform brown 

 above; young with alternating blotches above; 



ventrals 145 to 155 A. erythrogaster. 



hi Scales in 27 to 33 rows. 



Ci Two anterior temporals; dorsal and lateral alternating 



rows of isolated large square spots A. taxispilota. 



Co One anterior temporal; narrow dorsal and lateral spots, 

 di Eye in contact with labials; pattern conspicuous. 



forming diamonds on back A. rliomhifera. 



do Eye separated by subocular from labials; pattern 



indistinct, not forming diamonds A. cyclopion. 



N. septemvittata (Say). Moon-snake; queen-snake. Length 600 

 mm.; tail 120 mm.; color dark brown, with 3 narrow, black dorsal 

 stripes, often indistinct, and a bright yellow lateral band; belly yellow, 

 with 2 brown bands: United States east of the Alississippi, except New 

 England and New York; common. 



N. rigida (Say). Length 560 mm.; tail 120 mm.; color brown, with 

 2 narrow black stripes; belly yellow, with 2 stripes or rows of black 

 spots: South Carolina to Louisiana. 



N. grahamii (Baird and Girard). Length 640 mm.; tail 120 mm.; 

 color brown with a pale middorsal band and a broad pale or yellow 



