Reptiles 105 



and Henderson as found by H. G. Smith at Wray. Related to 

 these land forms is the Painted Turtle (Chrysemys marginata 

 belli of Gray), which abounds in lakes near Boulder and Denver. 

 It is elegantly marked with yellow, orange or red. There are 25 

 marginal plates on the carapace. 



The Soft-shell Turtle (Amyda spinifer of Le Sueur), found 

 in the region of the South Platte, is covered with a thick leathery 

 skin, and the snout is long and tubular. The Snapping Turtle 

 (Chelydra serpentina of Linnaeus) is a large and formidable animal 

 representing a peculiar family, Chelydridae. It is known, among 

 other characters, by the long tail. In Colorado it occurs east of 

 the mountains, from the vicinity of Boulder to Wray. The 

 Yellow-necked Mud Turtle (Kinosternon flavescens of Agassiz), 

 which has been taken at Lamar, has a narrow carapace, elevated 

 in the middle, not over six inches long. The tail is very short. 

 The under side is yellow, and the neck bright yellow. 



In past ages, turtles and tortoises were apparently much 

 better developed in our region. The land tortoises of the genus 

 Testudo, related to the common tortoise of Europe, were numer- 

 ous and in some cases of great size. Cope describes five species 

 from the Oligocene beds on Horsetail Creek, Northeastern Colo- 

 rado, while Hay made known two from the Miocene Pawnee 

 Creek beds north of Sterling. Hay described an interesting 

 turtle as Glyptops depressus, of somewhat uncertain origin, but 

 supposed to have been collected by Cannon in Colorado. Another 

 member of this genus (G. plicatulus of Cope) is from the sup- 

 posedly Jurassic beds at Canon City. Probaena sculpta of Hay 

 is from the Atlantosaurus beds near Canon City. Other fossil 

 turtles are from the Arapahoe beds on Bijou Creek. 



Our lizards belong to three different families. The Scin- 

 cidae, or skinks, with smooth, polished scales, are represented 

 by the genus Plestiodon, with several species. The commonest 

 one is the Sonoran Skink (P. obsoletus of Baird and Girard), 

 found in the vicinity of Wellington, Greeley and Osgood. It has 

 five rather indistinct yellowish stripes, and is a large lizard, 

 growing to a length of a foot. Much smaller, blackish to olive 

 green, is the Blue-spotted Skink (P. guttulatus of Hallowell), 

 which Beardsley found in Las Animas County. We are also 

 indebted to Professor Beardsley for the discovery in Colorado of 



