852 13. COLUBRIDE 
Oklahoma; Brownsville, San Diego, Point Isabelle, Reuters- 
ville, Cameron County, San Antonio, Eagle Pass, Pecos, San 
Angelo, Helodes, Jeff Davis County, “South of Claren- 
don,” Kerrville, Texas; and Matamoras and Charco Escon- 
dido, Tamaulipas, and Ojo del Diable, Chihuahua, Mexico. 
Remarks.—Marcy’s Garter-snake may usually be dis- 
tinguished at a glance by its postoral crescents and the posi- 
tion of its lateral line. The dorsal spots of certain speci- 
mens resemble those of certain specimens of TJ’. 0. vagrans, 
but usually are larger. The gastrosteges ordinarily lack 
the dark markings which are so constant in J. 0. vagrans, but 
frequently are marked with black laterally. The posterior 
genials usually are longer than the anterior. 
Our specimens from Tucson were caught in mud puddles 
on the desert a mile or more from the river. 
192. Thamnophis megalops (Kennicott) 
Mexican GARTER-SNAKE 
Plate 94 
Eutenia megalops Kennicott, Proc. Acad. Nat. Sci. Phila., 1860, p. 
330 (type locality, Tucson and Sta. Magdalena, Arizona); 
Corr, Report U. S. Nat. Mus. for 1898, 1900, p. 1025; Brown, 
Proc. Acad. Nat. Sci. Phila., 1901, p. 21; Dirmars, Reptile Book, 
1907, ps 221. 
Eutenia macrostemma Kennicort, Proc. Acad. Nat. Sci. Phila., 1860 
Pp- 331 (type locality, City of Mexico); Cope, Report U. S. Nat- 
Mus. for 1898, 1900, p. 1029. 
Eutenia flavilabris Cope, Proc. Acad. Nat. Sci. Phila., 1866, p. 306 
(type locality, tableland or southern mountains of Mexico); 
Cope, Proc. Am. Philos. Soc., 1884 (1885), p. 173. 
Eutenia insigniarum Cope, Proc. Am. Philos. Soc., 1884 (1885), p. 172 
(type locality, Chapultepec, Mexico). 
Tropidonotus ordinatus var. macrostemma BouLeNGER, Cat. Snakes Brit. 
Mus;,; Vol. 15.1893, p. 212. 
