1901.] NATURAL SCIENCES OF PHILADELPHIA. 99 



Sistrurus catenatus catenatus Italhicsque. 



I. c, 41 ; Crotalophorus tergeminus and C. Kirtlundii B. and G., 

 I. c, 14, 16. G. c. catenatus Cope, I. c, 685 ; Sistrurus catenatus 

 (part) Boul., I. c, III, 570 ; S. catenatus Stej., I. c, 411 ; S. c. cate- 

 natus Cope, Rep. Nat. Mus., 1146. 



In this northern race, the scale rows are usually 25, but occa- 

 sionally 23 or 27 ; the dorsal spots are larger and fewer in number 

 than in eonsors, being generally from 37-41 in number, of which 

 3-5 are on the tail, but an occasional example has them as numer- 

 ous as in the southern form. No. 7,241 Academy coll. is a 

 catenatus from Fort Kiley, Ivans., with 27 rows of scales and 44 

 dorsal blotches, of which 9 are on the tail, leaving the number of 

 body spots about as they should be. No. 7,240 has also 27 rows, 

 and only 37 spots, with a black belly. Nos. 7,243-44 are two 

 interesting specimens, collected together in INIichigan; the former 

 has 23 rows and 37 spots and the belly is immaculate yellow; the 

 other one has 27 rows and the belly is wholly black. 



The colors are usually darker and the lateral spots more distinct 

 than in eonsors. Occasional examples are entirely black. Ven- 

 trals 136-150; subcaudals 17-29. 



Length about 900 mm. 



Hab. — Ohio to Kansas, and north into Canada. Formerly 

 found in western New York, but it has now disappeared from most 

 cultivated localities. 



Sistrurus catenatus eonsors B. and G. 



Crotalophorus eonsors and C. Echcardsii B. and G., I. c, 12, 15 ; 0. 

 c. edwardsii Cofe, I. c, 685 ; Sistrurus catenatus (part) Boul., I. c, 

 III, 570 ; Garman., Bull, Ess. Inst., XXIV, 101, 1894 ; S. c. eonsors 

 and S. c. edicardsii Stej., I. c, 415, 416 ; S. c. edicardsii Cope, Rep. 

 Nat. Mus. 1144. 



!: Compared with the preceding this subspecies is probably rather 



smaller; the scutellation is similar, but the scale rows are usually 



23, though sometimes 25; the dorsal spots are smaller and more 



numerous, being in most cases 40-50 in number, of which 4-6 are 



on the tail. V^ariations toward S. c. catenatus are not uncommon, 



however; No. 7,234 Academy coll. from Hennessey, Okla., 



labeled edioardsi, has 25 rows of scales and 44 spots, and No. 



7,235, from Texas, has 23 rows of scales and but 37 spots. 



The correct name of the southwestern form of Sistrurus has 



been iu doubt, owing to the loss of Baird and Girard's type of 



C. eonsors, and the omission of some important details from their 



