1901.] NATURAL SCIENCES OF PHILADELPHIA. 97 



blackish browu ; an obli(|ue streak behind the eye and a yellowish 

 white band on the upper labials. 



Hab. — North Carolina and Florida, through the Gulf ^States to 

 Texas; up the Mississippi valley, occasionally to Illinois. 



The name ' ' water moccasin, ' ' properly belonging to this species, 

 is often wrongly applied to large, dark individuals belonging to 

 Tropidonotus ; but the shape of the head, the presence of the loreal 

 pit, and the sharply tapering tail, easily distinguish it. 



Anoistrodon contortrix L. 



Boa contortrix L. Syst. Nat., Ed. XII, 373; Agklslrodon contortrix, 

 B. and G., I. c, 17 ; Stej., I. c, 401 ; Ancistrodon contortrix Cope, 

 I. c, 683, and Rep. Nat. iMus., 1135 ; Boul. I. c. III, 523. 



Smaller and less stout than A. pisclvorus; no post-parietal plates; 

 loreal present; eye entirely separated from labials by the sub- 

 oculars; upper labials 8 (occ. 7); scales in 23 rows (rarely 25); 

 ventrak 145-155; subcaudals 31-52, some of the anterior ones 

 usually undivided. A large specimen from Pennsylvania measures 

 1,000 mm. (tail 130). 



Body color peculiar yellowish pink, often pale drab, crossed by 

 ■irregular brownish red bands with darker borders, wider and often 

 with pale centres on the sides; a series of small circular brownish 

 red spots on outer rows and ends of the ventrals, anteriorly these 

 are mostly on the ventrals; belly yellowish or pink, some.times 

 maculated with darker; chin and throat yellowish white; sides of 

 head cream color; top often bright copper, whence the name 

 " copperhead." In life, the markings vary greatly in outline and 

 richness of color. 



Hab, — Massachusetts south to Florida; west to Illinois, Okla- 

 homa and central Texas. 



SISTRURTJS Garman. 



No. Amer. Kept., 110 (1833); Crotalophorm B. and G., I. c, 11; 

 Cope, I. c, 684; Sistrurus, Boul., I. c, III., 569; Stej., I. c, 410; 

 Cope, Rep. Nat. Mus., 1140. 



A pair of large erectable, perforated poison fangs in front of 

 upper jaw : no other maxillary teeth; loreal pit and rattle present; 

 top of head covered with large plates; scales keeled, wuth pits, in 

 21-25 rows; anal and subcaudals not divided; sizes small to 

 medium. 



Hab. — North Amei'ica and Mexico. 



