936 REPORT OF NATIONAL MUSEUM, 1898. 



very deep. Heuce it has been overlooked by various authors. It is 

 this- character which separates it from Contia, to which some of its 

 species have been referred. The known species are found in the 

 Souoran and Toltecan subregions and in the adjacent parts of the 

 Central American region. All are of small size. They differ as 

 follows: 



I. Scales in 13 rows. 



Ventrals 126-137; luosteges 37-46; pale brown with faint longitudinal lines. 



C. taylorii Bonlenger. 



II. Scales in 15 rows. 



Gastrosteges 145-153 ; urosteges 35-57 ; pale brown, with or without darker cross- 

 bands or faint lines C. episcopus Kennicott. 



Gastrosteges 158; urosteges 34; rosy and white, with single black annulus or 

 semiannulus ; a black occipital cresent C. occipitalis Cope. 



Gastrosteges 152-173; urosteges 37-45; red, with pairs of black cross-bands 

 inclosing yellow ones C. michuacnnenais Duges. 



III. Scales in 17 rows. 



Occipital plates broad, regularly rounded; rostral prominent, convex above; 

 jDregeneials short, in contact with three labials ; belly sjiotted . . C. diasii Cope. 



Occipital plates longer, with undulate and emarginate posterior border; rostral 

 concave above; pregeneials longer, in contact with four labials; below un- 

 spotted C. varians Jan . 



The shallowness and position of the groove of the last maxillary 

 tooth in this genus does not entitle it to be placed in the Ojjisthogly- 

 pha. It may be perhaps in a condition from which the true groove of 

 the opisthoglyijhous tooth may have arisen. 



CHIONACTIS TAYLORII Boulenger. 



Contia taylorii Boulenger, Cat. Snakes Brit. Mus., 11, 1894, p. 265, pi. xii, fig. 3. 



Rostral broader than deep, the portion visible from above one-half to 

 two-thirds as long as the distance from the frontal; nasal undivided; 

 suture between the internasals as long as or shorter than that between 

 the XJrefrontals ; frontal about once and a half as long as brond, broader 

 than the supraocular, longer than its distance from the end of the snout, 

 a little shorter tlian the parietals; lorcal small, longer than deep; one 

 preocular and two postoculars; temporals 1 -|- 1 or 1 -^- 2; seven upper 

 labials, third and fourth entering the eye; three or four lower labials in 

 contact with the anterior chin shields; posterior chin shields very small 

 and separated from each other. Scales in 13 rows. Ventrals 126-137; 

 anal divided; subcaudals 37-46. Pale brown above, each scale darker 

 along the center; upper lip and lower i)arts white. 



Measurements. — Total length, 270 mm.; tail, 55 mm. 



Texas, probably the southwest (San Diego, Duval County). 



I have not seen this species, but the small number of scales and gas- 

 trosteges indicate its distinctness. Judging from Boulenger's figure, 

 it closely resembles the C. episcopus episcopus. 



