CROCODILIANS, LIZARDS, AND SNAKES. 



973 



NATRIX FASCIATA PLEURALIS Cope. 



Scutellation as in the species generally ; scales in twenty-three rows, 

 the inferior more weakly keeled and of larger size than the others. 

 Internasals longer than wide; oculars 1-3; middle of orbit above 

 suture between fourth and fifth superior labials. 



The color characters are quite peculiar. On tlie anterior part of the 

 body brown bands cross the ground color reacliing to the gastrosteges, 

 the lateral parts having parallel sides, and being separated by spaces 

 wider than themselves. The dorsal i)arts of these cross-bands grad- 

 ually disappear and posterior to the middle or last third of the length 

 are wanting, so that the coloration consists of lateral erect parallelo- 

 grammic spots separated by spaces of a yellow or gray ground color, 

 equal to or a little wider than themselves. Belly yellow, with brown, 

 rounded spots on the anterior parts of the gastrosteges; spots few on 

 the anterior third in the type. Head brown without markings; labials 

 lighter. 



Cat. Xo8. 



Gastrosteges. Urosteges. Scales. 



1092. 

 8786. 



131 + 1. 

 144 -fl. 

 136 -fl. 



301 

 73. 



23. 

 23. 

 23. 



Length. 



mm. 



517. 



1087 to anus. 



120? (? injured). 



(injured). 



This form is Austroriparian, but seems to be rare, as but two specimens 

 have come under my observation. They approach the forms of N. 

 sipedon, with lateral spots well separated. 



The large specimen, Cat. No. 8786, referred to this subspecies, is so 



dark colored that the pattern is only made out when immersed in fluid. 



The belly also is marked by narrow transverse blotches on the external 



parts of the gastrosteges, which afterwards blend and involve the 



whole surface. 



Natrix faaciata pleuralis Cope. 



NATRIX FASCIATA TRANSVERSA HalloweU. 



Tropidonotns iraiisverxiis 1I.\llowkll, Proc. Acad. Nat. Sci. Phila., 1852, p. 177. 

 Xerodia Iratisverm liAiHD and Giraud, Cat. \. Anier. Kept., Ft. 1, Serp., 1853, 



p. 148. 

 Nerodia woodhousei Bairu and Gikahd, Cat. N. Amcr. Roiit., Pt. 1, Serp., 1853, 



p. 42; Reptiles U. S. Pac. R. R. Surv , X, 1859, Whipple's Report, p. 41. 



Dorsal rows of scales twenty-five, all carinated. Three series of sub- 

 quadrate black blotches, a dorsal and two lateral, the latter vertically 

 elongated. A double yellow occipital spot. A yellow spot between 

 the supercilliaries and frontal ])lates. A black vitta from posterior rim 

 of eyes to angle of mouth. 



