6 Trans. Acad. Sci. of St. Louis 
Collared Lizard, Mountain Boomer, Black Shouldered 
Lizard, Bull Lizard, Gray Nellie. 
Description—Head large and sub-triangular; body 
thick; tail long and tapering to a point; supraocular 
scales usually small, excepting for a few enlarged ones 
near the center; supraocular area rising above interorbi- 
tal area; ear opening large and prominent, with an an- 
terior denticulation; tympanum exposed; one gular 
fold well developed, three sometimes present; labials not 
oblique or overlapping; lower series larger than upper 
series. 
All body seales finely granular; scales of back and 
sides about equal in size; ventrals larger; femoral pores 
distinct, well developed, with white, brown, or black cen- 
ters, enlarged in males, small in females; number, from 
fourteen to twenty-five; back part of mouth cavity black; 
males with one or more pairs of enlarged post-anal 
plates; females usually with even transverse scutellation 
behind anus. 
Coloration varies; colors well defined in nature, but 
fade to dull shades in captive specimens; coloration 
lighter at high temperatures and darker at lowered tem- 
peratures*; ventral color varies from a medium brown- 
ish to an immaculate white, through various shades of 
greens, grays, and blues; Kansas specimens without 
black or brown loin patches; dorsal ground color varies 
from blackish gray to light bluish gray; usually with 
pale dots which have no definite order of arrangement; 
light colored bars extending transversely across the dor- 
sal surface in certain specimens; back often with scat- 
tered flecks of brown, orange or reddish; lower jaws 
*Franklin (1913) found that “During the cooler hours of the day 
these liz izards were a dark dirty gray, but when the air was warm an 
~ lizards became more peri the color changed to a bright emerald 
