CROCODILIAN8, LIZARDS, AND SNAKES. 1111 



TI. Superior labials, seven; orbitiils, 1-1. 



Coloration niiiforai T. jihiviceim IJlainville 



III. Superior labials, seven; two poatorbitals. 



a. Postnasals in fcontact with preocnlar, or nearly so. 



/i. Posterior labials elevated, separated from parietals b}' ouo temporal. 

 Form slender; a yellow, black-bordered eollar near parietal plates; 



below red T. miniata C'<)pe. 



fif3. Posterior labials elevated, bounded above by two temporals. Labials 

 lii<;lier; lirst inferior labials separate; black, with wide yellow 



collar T. vuista (iiinther. 



Frontal narrower; posterior labials higher, body banded. 



7'. melanocephala Linnanis. 

 Frontal wider; posterior labials lower; body uniform red. T. rubra Cope. 

 /?/i/i. Posterior labials low, bounded above by two temporals. 

 y. Inferior labials of first pair in contact with middle line. 



Postnasal very small; collar far behind head; body banded; uros- 



teges, 51 T. armiUata Cope. 



Postnasal large; collar crossing parietal scuta; body unicolor. 



T. coronata Baird and Girard. 

 yy. Inferior labials separated by symphyseal. 



Urosteges, 67; postnasal large, bounded below by first labial; a yel- 

 low collar T. reticulata Cope. 



Urosleges, 57; postnasal chiefly bounded bj^ second labial; head 



black ; no collar T. ni<iric.eps Kennicott. 



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



T. canida Cope. 

 Urosteges, 25 ; nasals not interrupted by first upper labial; head 



dark with a pale occipital spot T. vermiformis Hallowell. 



cxa. Postnasals separated from preocnlar by a wide space. 



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



T. pallida Cope. 



Urosteges, 66; last upper labial larger than sixth ; body above with 



black and white half-rings T. semicincta Dumeril and Bibron. 



Professor Jan ' describes a T. {Homalocranium) wagneri said to have 

 been taken in Florida. It is described as having an entire anal plate, 

 and does not therefore belong to this geuns. It has not been observed 

 by American naturalists. It is said to have seven superior labials, and 

 the scales in 15 series. It is reddish white above, with a black half 

 color on the nape. This is separated from the dusky top of the head by 

 a white cross band, and there is a white spot behind the eye. 



TANTILLA GRACILIS Baird and Girard. 



Tantilla gracilis Baird and Giraud, Cat. Serp. N. Amer., 1853, p. 132.— Cope, 



Check-list N. Amer. Batr. Rept., 1875, p. 35. 

 Homalocranium (jracileBocovRT, Mission Scient. Mexique, 1883, p. 579, pi. xxxvi, 



fig. 5.— Jan, Icon. Gen. Ophid., Ft. 15, 1866, pi. ii, fig. 1. 

 Tantilla hallowellii Cope, Proc. Acad. Nat. Sci. Phila., 1860, p. 77. 



Anterior and postorbitals one each. Color uniform greenish brown 

 above, lighter beneath; head darker. 



Vertical plate subhexagonal, much shorter than in T. coronata. Post- 



Archivio per la Zoologia, Modena, December^ 1861, p. 51. 



