98 BULLETIN 61, UNITED STATES NATIONAL MUSEUM. 



THE SAURITUS GROUP. (PROXIMUS, SAURITUS, SACKENI.) 



PROXIMUSfi 



Description. — Contrary to most forms in the genus, there is Kttle 

 danger of confusing proximus with any other garter-snake. The 

 stripe is always upon the tliird and fourth rows and the form is long 

 and slender, the tail forming .25 to .37 of the total length. The 

 dorsal scale rows are nearly always 19-17 (in the southern part of 

 the range occasionally 17-19-17) and the labial formula is usually 

 8/10, only occasionally 8/9 or 8/11, and more rarely 7/10 or 7/9. 

 The ventral scutes vary between 150-179 and the urosteges between 

 75-125. 



In coloration proximus closely resembles the other forms of the 

 group. The ground color varies from light olive to brown or black 

 and is never broken up by distinct spots, although a narrow irregu- 

 lar black band is generally found along the stripes in specimens light 

 enough to show it and many of the scales may have black edges and 

 bases. In some of the paler specimens examined the usual two rows 

 of alternating spots are distinct upon the skin, but in by far the 

 majority of specimens these spots are fused more or less, so that the 

 skin between the scales is usually black with numerous white lines 

 irregularly disposed. The stripes may be of a bluish, yellowish, or 

 greenish tint (the dorsal rarely reddish, occasionally brown), and 

 the lateral is in every specimen examined upon the third and fourth 

 rows; the dorsal usually occupies the median and the halves of the 

 adjacent rows, but occasionally covers nearly all of the adjacent 

 rows. The superior labials are always quite pale, occasionally red- 

 dish, in color and nearly always lack the black border that is found 

 throughout all of the other groups. The ventral surface is gener- 

 ally bright yellowish, greenish, or bluish, and without or with very 

 small and mostly concealed ventral spots. 



Habits and hahitat relations. — Very few records of observations 

 upon the habits of this snake can be found. Under the name Eutse- 

 nia saurita yslt. faireyi, Taylor (1892, 322) writes for Nebraska that 

 the food '' consists mostly of insects and their larvae, but also includes 

 fish, frogs, etc." Upon what authority this statement is- made we 

 do not know. In regard to three specimens taken at Progreso, 

 Yucatan, Dr. L. J. Cole has written me as follows: "All of the speci- 

 mens [three] were found in the water (brackish) in the mangrove 

 swamps back of Progreso. One other specimen was seen, and that 

 also was swimming in the water. I saw none of them on land." 

 Cope says (1880, 23) that it is "like the E. saurita, aquatic in its 

 habits." 



aThamnophis sauritus proximus (Say), Long's Exped. Rocky Mts., 1823, p. 187. 

 Includes Eutsenia rutiloris Cope and E.faireyi Baird and Girard. 



