CROCODILIANS, LIZARDS, AND SNAKES. 871 



transverse jet-black bars across the tail. Abdomen yellowish, thi(;kly 

 maculated with black patches. 



Head proportionally large, ovoid, distinct from the body. Snout 

 pointed. Parietal plates small. Frontal broad, sub[)entagonal, slightly 

 concave on the sides. Superciharies large. Internal prefrontals rather 

 narrow, elongated; external prefrontals quadrilateral, a little broader 

 forward. Internasals irregularly quadrangular. Kostral very narrow, 

 extending halfway between the prefrontals, convex, and raised above 

 the surface of the snout. Nostrils in the middle line between the nasals, 

 the posterior of which is a little the smaller. Loreal trapezoidal, propor- 

 tionally large. Inferior auteorbital very small, resting upon the fourth 

 upper labial. Postorbitals varying in comparative size. Temporal 

 shields small, resembling scales. Upper labials eight to nine, sixth 

 and seventh the larger. Lower labials twelve, sixth and seventh largest. 

 Posterior mental shields very small, extending to oi)posite the junction 

 of the seventh and eighth lower labials. Scales proportionally small, 

 in twenty-nine to thirty-three rows, the six outer ones perfectly smooth 

 and somewhat larger than the remaining rows. 



Ground color yellowish-brown, with three series of dorsal black 

 blotches, forty-five to sixty five in number, from the head to oi)posite 

 the anus, with twelve on the tad, in the shape of transverse bars. 

 Those of the medial series the larger, and covering eight or nine rows 

 of scales. On the anterior part of the body they are subcircular, 

 embracing longitudinally four scales; posteriorly they become shorter 

 by one scale. The light spaces between are a little narrower than the 

 blotches themselves for the twelve anterior blotches and wider than 

 the blotches for the remaining length of the body. The blotches of the 

 adjoining series alternate with those of the medial series, being oj^po- 

 site to the light intermediate spaces, across which the blotches of either 

 side are generally united by a transversal narrow band. The flanks 

 are densely covered with small aud irregular blotches, forming three 

 indistinct series, confluent in vertical bars toward the origin of the 

 tail. Inferior surface of the head yellowish, unicolor. Abdomen dull 

 yellow, with crowded brownish-black blotches in series on the extremity 

 of the scutella. 



Baird and Girard give the following numbers of scuta and scales, 

 with dimensions in inches: 



Cat. No. 1540; Red River, Arkansas; gastrosteges, 231; iirosteges, 52; rowsof scales, 

 35; totallength, 38J ; tail, 4 J. 



Another specimen, same locality ; gastrosteges, 231 ; nrosteges, 52; rows of scales 

 33; total length, 24*; tail, 2J. 



I add the following: 



Cat.No8. Locality. Gastrosteges. TTrosteges. Scales. 



1516. Rush Lake, Souora 219. 63. 27. 



1548. Lower Rio Grande, Texas 238. 46. 31. 



1561. Rock Island, Illinois 221. 59. 27. 



1543. Poplar River, Montana 215. 60. 29. 



