222 



VERTEBRATE ANIMALS OF THE UNITED STATES 



Fig. 125. 



-Agkistrodon piscivorus {from 

 Cope). 



A. piscivorus (Lacepede). Water moccasion; cottonmouth (Fig. 

 125). Length 1,000 mm.; tail igo mm.; color olive brown, crossed by 

 20 to 30 obscure darker bands; head purplish black; belly yellow, with 



black blotches: Atlantic and Gulf 

 drainage from Virginia to eastern 

 Texas; semiaquatic, often common 

 along streams, feeding on frogs, fish, 

 rodents and birds, for which the 

 snakes will often lie in wait, perched 

 in bushes overhanging the water; bite very dangerous. 



2. Sistrurus Garman. Rather small snakes, with head covered 

 with 9 symmetrical plates, and with a small rattle composed of not 

 more than 8 rings; scales in 21 to 25 rows; upper labials 10 to 12; ven- 

 trals 125 to 145; subcaudals, except a few of the terminal ones, undi- 

 vided: 3 species, i in Mexico. 



S. catenatus (Rafinesque). Massasauga (Fig. 126). Length 800 

 mm. ; tail 100 mm. ; color light brown, with a middorsal series of 30 to 36 

 irregular dark brown blotches, each one edged with white; and 3 similar 

 laterals series; belly mottled brown; melanistic coloring not uncommon; 

 scales in 23 or 25 rows; upper labials 11 or 12: western New York to 

 Nebraska; southward into Texas and Mexico; in wet 

 fields and swamps, feeding on frogs and other small 

 animals; bite very dangerous. 



S. 

 darker 

 range. 



S. 



Subspecies of S. catenatus 



c. catenatus (Raf.). Scales in 25 rows; colors 

 ; blotches larger: eastern and central parts of 



Fig. 126. — Sis- 

 tnirus catenatus 

 (from Cope). 



c. edwardsii (Baird and Girard). Scales in 23 

 rows; colors paler; blotches smaller: Oklahoma and 

 western Texas. 



5. miliarius (L.). Ground rattler. Length 430 mm.; tail 60 mm.; 

 color gray, yellowish or brown, with a middorsal series of about 40 

 irregular spots or cross bars and i or 2 lateral series of smaller spots on 

 each side; belly white, with numerous dark blotches; scales in 21 to 23 

 rows; upper labials 10 or 11: Atlantic and Gulf drainage from central 

 North Carolina to Texas, and up the Mississippi Valley to Arkansas 

 and Oklahoma; in wet places; the least dangerous of the rattlesnakes. 



3. Crotalus L. Rattlesnakes. Head covered with scales, most 

 species having also small plates between and in front of the eyes; rattle 

 large and composed of at most 14 rings; scales in 23 to 31 rows; upper 



