Illinois Reptiles and Amphibians. 187 



Ophisaurus rrnfralis, Linn. 



Formerly common on the prairies of the central part of 

 the State, but now being rapidly exterminated there by the close 

 grazing and cultivation of the land. Still rather common in 

 southern Illinois. 



Oligosoma laterale. Say. 



Occasional in Southern Illinois. 



Agkistrodon piscivorus^ Holbr. 



Extremely common in bottom-land pools along the Missis- 

 sippi River in southern Illinois. 



Coluber constrictor, Bd. & Gir. 



The prairie form of this species is of a dull slate-color above, 

 becoming blue on the sides and belly. It is known everywhere 

 as the blue racer. In southern Illinois the more slender black 

 variety is common. The " black snake " of the prairie regions 

 is very frequently a different species, — the Elaphis obsoletus. 



Eidaniia radix., Bd. & Gir. 



In the latest edition of his Manual of the Vertebrate Ani- 

 mals of the Northern U. S., etc., Prof. Jordan gives the distri- 

 bution of this serpent as "Wis. to Oregon." It is certainly 

 very common in the central part of Illinois, as far south as 

 Champaign county. I have not seen it in Kentucky. 



Tropidocloniiim lineata, Hallowell. 



This is the type of HallovveH's genus Microps ( preoccupied) 

 and of Cope's genus Tropidoclonium. The anal plate is entire, 

 while in Begina kirtlandi, a species often placed in the genus 

 Tropidoclonium, it is divided. Three examples were taken at 

 Urbaua, Illinois, in April, 1889, The largest of these meas- 

 ured 13^ inches in length, and was thus considerably larger 

 than the example from which the original description was 

 drawn. The three examples from Illinois differ from Hallo- 

 well's type in that the eye is above the third supralabial plate, 

 not above the third and fourth. 



Head small, not marked off from the body. Eye very small. 

 One nasal plate, grooved below the nostril. Loreal present. 

 One auteorbital; two postorbitals; two small internasals; two 

 prefrontals. Frontal longer than broad, sides nearly par- 



