32 rROCEEDiXGS OF Till: ACADEMY OF [Jaa., 



TROPIDONOTUS Kuhl. 



Isis von Oken, 1826, 205 ; Boul. (part), I. c, I, 192 ; Natrix Cope, I. c, 

 667, and Kep. Nat. Mus., 957 ; Nerodia and Rerjiaa B. and G., I. c, 

 38-45. 



Maxillary teeth smooth, gradually increasing posteriorly, the 

 last three or four rather abruptly enlarged; head scales normal; 1 

 loreal; 2 [nasals; 2 interuasals; body rather stout; head distinct; 

 scales keeled with double pits in 17-38 rows; anal divided. 



Hab. — Europe, Africa, Asia, Australia, America. 



This genus much resembles Eukeiiia, but has a divided anal and 

 scale pits. Being viviparous, like Eutcenia, these snakes breed 

 freely in captivity, and the insignificance of slight differences in 

 color and pattern may be instructively observed in almost any 

 single brood of young. 



Key to the North American Species. 



a. — Body with stripes; scales in 19-21 rovvs: 

 a\ — Preoculars 2 : 



Brown; 3 black stripes on back; 4 on belly, 



1. T. leberis. 

 Olive brown, with 4 narrow stripes on back, 



2. T. grahami. 

 Brown, with 2 narrow stripes on back, 3. T. rigida. 

 h\ — Preocular 1 : 



Yellowish brown; 4 dark brown sti'ipes on back, 



4. T. clarki. 

 h. — Body with spots or cross bands: 



a\ — Scales in 19-21 rows ; brown, with indistinct spots or 



cvoss-bands, 5. 21 conipressicauda. 



b\- Scales in 23-25 rows ; brown with alternating spots or 



cross-bands, 6. T. sipedon.^^ 



\ c\ — Scales in 27-29 rows: 



27 rows; large alternating spots, . 7. T. rhombifer. 

 29 rows; narrow coss-bands; eye with circle of scales, 



8. T. cyclopeum. 



d\ — Scales in 29-33 rows; size large; alternating spots; 



parietals broken up, T. taxisjnlotus. 



Tropidonotus leberis L. 



Coluber leberis L., Syst. Nat., Ed. X, 216 (1753); Regina leberis B. 

 and G., I. c, 45 ; JS^atrix leberis Cope, /. c, 668, and Eep. Nat. Mus., 

 993 ; T. septemvittatus Boul., I. c, 1, 239. 



Size moderate ; oculars 2-2 ; temporals 1-2 ; upper labials 7 ; 



1^ Tropidonotus bisectus Cope {Proc. U. S. Nat. 3Ius., 1887, p. 116) Is 

 obviously abnormal in some, at least, of its characters. Its locality is uncer- 

 tain and is probably referable to some form of T. sipedon. 



