598 NORTH AMERICAN SNAKES COPE. 



CC. Inferior labials separated by symphyseal. 



Urosteges G7 ; postnasal large, bounded below by first labial ; a yellow collar. 



T. reticulata Cope. 

 Urosteges 57 ; postnasal chiefly bounded by second labial ; head black, no 



collar T. nigricepis, Kcnn. 



Urosteges 39 ; first labial rising to nostril ; head and body uniform. 



T. canula, Cope. 

 Urosteges 25 ; nasals not interrupted by first upper labial ; head dark with 



a pale occipital spot T. vermiformis, Hallow. 



AA. Postnasals separated from preocular by a wide space. 



Urosteges 57 ; unicolor, pale ; top of head and collar black. 



T. pallida, Cope. 



Urosteges 60; last upper labial larger than sixth; body above with black 



and white half-rings T, semicincta, D. and li. 



Tantilla gracilis Bd. and Gird. 



Cat. Serp. N. Amer., 1853, 132; Cope Check List, 1875, p. 35; Homalocrauium f/racile 

 Bocourt Mission Scient., Mexique 1883, p. 579, PI. xxxvi, Fig. 5; Jan, Icon. Gen. 

 Ofid. I, 15 ii, Fig. 1. Tantilla hallowellii Cope, Proc Acad. Phila. 1860, p. 77. 



The postnasal and preocnlar plates are sometimes separated in this 

 species. On such a specimen the T. hallotveUii was proposed. 

 Western Texas. 



Tantilla planiceps Blainv. 



Cope, Jour. Acad. Phila., 1875, p. 143; Coluhcr planiceps Blainville, Amer. Mus. Hist. 

 Nat., Paris, iii, 1834, p. 62, PI. xxvii. Figs. 3, 3a, Ml) ; Homalocrauium planic(pii 

 Dum., Bibr. Erp. Gen. vii, 1834, p. 857; Bocourt Miss. Sci. Mex., 1883, p. 581, PI. 

 XXXVI, Fig. 7; Jan, Icon. Gen. Ofid. I, 15 ii, Fig. 2. 



Lower California.' 



Tantilla nigriceps Kennicott. 



Proc. Acad. Phila., 1860, p. 3:8; Cope Check List Batr. Rept. N. Amer., 1875, p. .35; 

 Sco'ccoi)hisf nmice2)S Coiie, Proc. Acad. Phila., 1860, p. 371; Homalocrauium praeo- 

 culum Boc. Miss. Sci. Mes. Rept., 1883, p. 582, PL xxxvi. Fig. 8 (abnormally with 

 two ])reocular plates). 



In a specimen of this species from southwestern Texas there is but 

 one postocular on one side. 

 Texas generally, except the east. 



Tantilla coronata Bd. and Gird. 



Cat. Serp. N. Amer., 1853, p. 131; Cope, Jour. Phil. Acad., 1875, p. 144 ; Homalocrauium 

 coronatum Bocourt Mission Sci. Mexique Reptiles, 1883, p. 589, PL xxxvii, Fig. 5; 

 Homalocrauium wa(juerii Jan, Icon. Gen. Ofid. I, 14 ii, Fig. 3. 



Gulf States to Florida inclusive. 



In its distribution this species extends much farther east than any of 

 its North American congeners. It is yet rare in museums. A speci- 

 men is in my collection from Volusia, Lake George, Florida. 



