13. C0LURR1D.7. 



Distributjo)!. — This beautiful little snake ranges from 

 Kansas and Texas west to Arizona. In the latter state it has 

 been taken in Pima County, where we found it under stones 

 on the banks of the Santa Cruz River near Tucson, and in 

 Ventana Canyon near the base of the Catalina Mountains. 

 McLain records a specimen taken in the mountains near 

 Tempe, Maricopa County. 



I have received a specimen from St. George, Washing- 

 ton County, Utah. 



Remarks. — This Tantilla is readily distinguished from 

 the Calif ornian T. eiseni by its fewer gastrosteges (135 to 

 148 as against 167 to 181). Tantilla planiceps of Lower 

 California has only 138 to 140 gastrosteges, but its nuchal 

 collar is on the sixth and seventh rows of scales behind the 

 parietals. T. wilcoxi has a larger number of gastrosteges 

 ( 148 to 1 57) and the white collar crosses the parietals. 



202. Tantilla planiceps (Blainville) 

 Lower California Tantilla 



Coluher planiceps Blainville, Nouv. Ann. Mus. Hist. Nat., Vol. IV, 

 i8j5, p. 294, pi. 27, figs. 3-3b (type locality, California); Baird & 

 GiRARD, Cat. N. Amer. Rept., Pt. I, Serpents, 185.3, P- i54- 



Homalocranion planiceps Dumeril, Mem. Acad. Sci. Paris, Vol. XXIII, 

 1852, p. 490; Dumeril et Bibron, Erpetologie Generale, Vol. 

 VII, 1854, p. 857; Jan, Arch. Zool. Anat. Phys., Vol. II, 1862, 

 PP- S'. 55; jANjElencosyst. degli Ofidi, 1863, p. 40; Jan & Sordelli, 

 Iconogr. gener. des Ophid., 15e livr., 1866, pi. II, fig. 2; Bocourt, 

 Miss. Sci. Mex., 1883, p. 581, pi. XXXVI, figs. 7-7d; Boulenger, 

 Cat. Snakes Brit. Mus., Vol. Ill, 1896, p. 226 (part); Mocquard, 

 Nouv. Arch. Mus. Hist. Nat., Ser. 4, Vol. i, 1899, p. 316. 



Tantilla planiceps Cope, Proc. Acad. Nat. Sci. Phila., 1861, p. 74; Cope, 

 Journ. Acad. Nat. Sci. Phila., 1875, p. 143; Yarrow, Bull. U. S. 

 Nat. Mus., No. 24, 1883, pp. 13, 190; Garman, Mem. Mus. Compr. 

 Zool. Cambr., Vol. VIII, No. 3, 1883, pp. 89, 163; Garman, Bull. 

 Essex Inst., Vol. XVI, 1884, p. 31; Cope, Bull. U. S. Nat. Mus., 



