VARIATIONS OF GARTER-SNAKES. 133 



HAMMOND I a 



Description. — This form, which was long considered a subspecies of 

 elegans, has in late years been given the rank of a species. Any general 

 description will not describe it accurately owing to the variableness of 

 the most distinctive characters. A grayish or brownish yellow stripe 

 on the second or second and third rows. Dorsal stripe usually wanting, 

 occasionally represented on the nape, rarely present for the entire 

 length and then but faintly. Dorsal scale formula, 21-19-17 (occa- 

 sionally 19-21-19-17). Supralabials, 8 (rarely 9). Infralabials, 10 

 (occasionally 9 or 11). Oculars, 2-3, 2-4, 1-2, or 1-3. Subcaudals, 

 65-96. Ventrals, 155-178. Proportionate tail length, .21-.27. 

 Color above the lateral stripes dark grayish or olive brown, marked 

 with four rows of small alternating black spots. First row usually a 

 little lighter than above and with or without a small black spot on the 

 base of each scute. Small nuchal blotches. Belly greenish or yellow- 

 ish ash without a median ventral shading formed by the median pro- 

 longation of the black bars at the base of the ventral scutes. 



Hahits and habitat relations (fig. 55) . — The only observations known 

 to me on the habits of this snake are those recorded by Van Denburgh 

 and Grinnell: 



Like other members of its genus, this snake swims well and is usually found in or 

 near water. Its food consists mainly of aquatic animals, such as fish, frogs, and tad- 

 poles. One specimen was caught with a good-sized trout in its teeth. (Van Denburgh 

 1897, 214.) 



This is the water snake of the mountain regions, and is abundant in summer along 

 the San Gabriel, Arroyo Seco, and Tujunga caijyons. It occurs also tho more spar- 

 ingly in the smaller canyons and out along the water courses a few miles into the valley 

 country. 



Many years ago before the pumps had drained the water from the Arroyo bed west 

 of Pasadena there was a good-sized stream there all summer. Along this stream the 

 California garter-snake was very common. There were sometimes four in sight at 

 once along the sandy banks. When alarmed they would take to the water and dis- 

 appear into the deeper places for a short time or swim gracefully across the brook and 

 crawl out on the opposite bank. 



This snake feeds on tadpoles, small frogs, and fish. We have seen a garter-snake so 

 gorged with tadpoles that when alarmed it had to give up some of its cargo, the 

 released tadpoles wriggling out of the snake's mouth apparently none the worse for 

 wear. (Grinnell, 1907, 49-50.) 



Range. — This species is only known from southern California and 

 northern Lower California. The specimens examined represent the 

 following localities: La Guilla, San Pedro Martir Mountains, and Sar 

 Antonio, Lower California; Twin Falls, Soda Springs, Los Angeles 

 San Bernardino County, San Diego County, Fort Tejon, Fresno, 

 Alvord, Cartago, Bishop, South Fork Kern River (25 miles above 

 Kernville), Kern River Lakes, Kern Lake, California; "Mohave 

 Desert, Arizona." 



oThamnnphis hammondi (Kennicott), Proc. Acad. Nat. Sci. Phila., 1860, p. 332. 

 Includes E. couchi and E. elegans couchi of various authors, but not of Kennicott. 

 33553— Bull. 61—08 10 



