BeptUes and AmphiJticms of Illinois. "ioS 



Ophisaurus ventralis, Linii. Joint -snake, Glass -snake. 



Angiiis ventrdlis, Linn., 8yst. Nat., 1760, p. 391. 



OpIiisfiuriLs ventralis, Dum. et j^ibr.. Erp. Gen., V., 1830, p. 423. 



-De Kay, Nat. Hist. N. Y., I., Zofd. III., Rept. and Amph. 



1842, p. 34; Holbr. N. A. Herp., 1842, II., p. 139,pl.20.-Gray, 



Cat. Spec. I>izards in Coll. Brit. Mns., 1845, p. 56. 

 Ophiosaurun lineatus, Kenn., Trans. III. State Agr. Soc, 1853-54, 



I., p. 591. 

 Opheosaiirus ventralis, D'dvis and Rice, Bull. 111. State Lab. Nat. 



Hist., I., No. 5, 1883, p. 48; Bull. Chicago Acad. Sci., 1883. 



Total length about twenty-eight inches. Body long and 

 slender. Scales equal in size above and below, those on the pos- 

 terior part of the body and on the tail with a slight median ridge 

 forming obtuse longitudinal carinas. Aperture of the ear small. 

 A deep groove extending from a short distance behind the ear 

 along the sides of the abdomen to the vent. Scales in a longi- 

 tudinal row from the parietals to a point opposite the vent, 

 about one hundred and twenty-five. Scales in a transverse row 

 about midway between the head and vent, twenty-four. Head 

 continuous with the body, compressed forwards and pointed. 

 Two series of supraciliary plates. Frontal large, widest behind. 

 Two small frontoparietals. Two large parietals and a pentag- 

 onal interparietal. Two prefrontals. Internasal large, as 

 broad as long. Seven suprauasals. Nasal plate small. Ros- 

 tral slightly wider than high. Eleven supralabials, the ninth 

 and tenth largest. Marginal series of infralabials elongate 

 and narrow. 



Color above clay yellow, or brown or greenish olive, with a 

 median longitudinal stripe of brown, and on each side above 

 the lateral grooves a wide black or brown stripe including 

 three narrow whitish lines. On the sides of the abdomen be- 

 neath the lateral grooves are two narrow dark stripes. Beneath 

 whitish, unspotted. 



Length of body to the vent 2S.2'^: tail beyond vent, 10. 



Throughout the State; rare in the north; formerly common 

 in central and southern Illinois, but now fast disappearing. 

 Cook Co. (Kennicott), Stark Co. (Boardman), Peoria ( Bren- 

 del). Normal, Wabash Valley (Ridgway). 



The colors of Illinois specimens of the joint snake are 

 generally disposed in distinct longitudinal dark and pale stripes, 



