180 BULLETIN 114, UlTITED STATES NATIONAL MUSEUM. 



County, Illinois, as Mr. Ridgway has collected extensively here but 

 not at Richland, which is in Sagamon County. Richland County 

 is in much better agreement with the specimen; its pattern is not 

 typical for syspilo., as here defined, but is closely approached by some 

 specimens from southeastern '-llinois and southern Indiana. Saga- 

 mon County is close to the range of triangulum, and an individual 

 like the type of sysjnla is not to be expected there. 



Description. — The scutellation, as exhibited by nearly a hundred 

 specimens, is as follows: Ventrals, 180 to 215; caudals, 40 to 54 

 (males, 43 to 54, average 48; females, 40 to 50, average 47); supra- 

 labials, 7; infralabials, 9, rarely 8 or 10; 1 preocular, very rarely 2; 

 2 postoculars, rarely 1; temporals commonly 2+2 + 3, or 2 + 3+4, 

 occasionally 1 + 2 + 3 ; posterior chin shields usually shorter than the 

 anterior, sometimes about as long, in contact with each other or 

 separated by a small scale; loreal distinctly longer than high; maxi- 

 mum number of scale rows commonly 21, often 23, very rarely 19, 

 beginning with 21 or 19 and ending with 19 or 17. 



In size and proportion this form is nearest like triangulum. The 

 head is scarcely distinct from the body, is tapering, and blunt; the 

 body is fairly stout, and cylindrical, except that the belly meets the 

 sides at something like a right angle; the tail is typically short and 

 tapers quickly to a horny tip. Of the total length, the tail varies 

 from 0.114 to 0.157 (males, 0.130 (0.116) to 0.156, average 0.137; 

 females, 0.114 to 0.146 (0.157), average 0.131). The largest speci- 

 men examined was from St. Clair County, Illinois, and measured 

 1060 mm. 



The pattern (fig. 68), although apparently in rings wheij viewed 

 from above, has definitely changed to the blotched or saddled type. 

 The whitish cross bands, varying from 23 to 36 (one specimen, 43) in 

 number, are IJ to 3 scales wide above and from one to several scales 

 wider on the lower rows. They are usually strongly mottled on the 

 sides with darker, and are narrowly bordered with black. The black 

 borders of adjacent pairs meet usually on the first or second row of 

 scales to inclose the dorsal saddles of the predominating color — red, 

 or brownish, or gray. These dorsal saddles vary much in width 

 but are usually decidedly broader than the groups of white and 

 black bands that separate them. The belly is generally strongly 

 checked with black and white. On the sides, usually overlapping 

 ventral and dorsal scales, is a series of small black blotches, often 

 inclosing some of the ground color, and alternating with the dorsal 

 saddles. These alternating spots are nearly always present (rai'ely 

 fused into a single midventral series), except in transitional individ- 

 uals from the western and southern limits of the range, where inter- 

 gradation occurs with the ringed forms, gentilis and amaura. 



The head typically shows a narrow black band across the posterior 

 extremities of the parietals, followed by a whitish haK collar on the 



