12. SISTRUBTTS. 571 



Crotalophorus tergeminus, Holbr. N. Am. Herp. 2nd ed. iii. p. 29, 



pi. V. (1842) ; Gray, Cat. p. 18 (1849) ; Agassk, Lake Superior, 



p. 381, pi. vi. figs. 6-8 (1850) ; Baird 8f Gir. Cat. N. Am. Rept. 



p. 14 (1853) ; Wied, N. Acta Ac. Leop.-Carol. xxxii. i. 1865, 



no. 8, p. 74. 

 kirtlandii, Holbr. t. c. p. 31, pi. vi. ; Gray, I. c. ; Baird 8r Gir. 



I c. p. 16. 



miliarius, part. , Gray, I. c. p. 17. 



consors, Baird ^ Gir. I. c. p. 12, and Rep, U.S. Explor. 



Surv. R. R. X., -ffiepi. pi. xxiv. fig. 8 (1859). 

 edwaxdsii, Baird ^ Gir. II. cc. p. 15, pi. xxv. fig. 10, and Rep. 



U.S. Mex. Bound. Surv., ii. Rept. ^. 15, pi. v. fig. 1 (1859); 



Duffh, Naturaleza, iv. 1877, p. 27. 



massasauga, Baird, Serp. N. York, p. 12 (1854). 



Orotalus miliarius, vars. edwardsii and tergeminus, Ja}i, Elenco, p. 124 



(1863), and Icon. Gen. 46, pi. iii. figs. 4 & 6 (1874). 

 Caudisona edwardsii. Cope, Chech-list N. Am. Rept. p. 34 (1875). 



tergemina, Cope, I. c. 



Orotalus catenatus, Garm. N. Am. Rept. p. 118, pi. ix. fig. 2 (1883). 

 Sistrurus catenatus, Garm. I. c. p. 176 ; Hay, Batr. Sf Rept. Ind. 



p. 126 (1892) : Stejneqer, Rep. U.S. Nat. Mm. f. 1893, p. 411, 



pi. V. (1895). ■ 

 Crotalophorus catenatus. Cope, Proe. U.S. Nat. Mus. xiv. 1892, 



p. 685. 



Distinguished from the preceding in having the upper prseocular 

 in contact with the posterior nasal above the loreal, which is very 

 small ; two or three series of scales between the eye and the labials ; 

 temporal scales smooth ; 11 to 14 upper labials. Scales in 23 or 

 25 rows. Ventrals 136-153 ; subcaudals 20-31. A dark spot on 

 the parietal shields, between, the two ocoipito-nuchal stripes ; a light 

 streak from the loreal pit to the angle of the mouth ; dorsal spots 

 usually larger than in S. miliarius, transversely elliptic or reniform. 



Total length 680 millim. ; tail 80. 



Great Lakes district ; United States East of the Eocky Mountains 

 and West of the Mississippi ; Northern Mexico. 



a. $ (Sc. 25 ; V. 143 ; 0. 22). Canada. J. Cruickahank, Esq. [P.]. 



h. cJ (Sc. 26 ; V. 139 ; C. 28). Illinois. Smithsonian Instit. 



c. S (Sc.25; V. 148; C. 22). N. America. 



d. d (Sc. 25 ; V. 146 ; 0. 31). ? 



3. Sistmrus ravus. 



Crotalus ravus, Cope, Proc. Ac. Philad. 1865, p. 191. 

 Caudisona rava, Cope, Check-list N. Am. Rept. p. 31 (1875). 

 Crotalus miliarius, var. ravus, Garm. N. Am. Rept. p. 120 (1883). 

 Crotalophorus ravus, Cope, Proc. Amer. Philoa. Soc. xxii. 1885, 

 p. 382, and Proe. U.S. Nat. Mus. xiv. 1892, p. 684. 



Canthus rostralis rounded. Rostral broader than deep, recurved 

 above; temporal scales smooth; 11 or 12 upper labials. Scales in 

 21 or 23 rows, the keels on the median dorsal scales thick. 

 Ventrals 147; subcaudals 26. Yellowish brown, with a dorsal 

 series of deep brown spots, longer than broad, and a series of trans- 



