MEXICAN SNAKES AND C'ROCODILIANS — SMITH 495 



Table 42. — Variation in Tropidodipsas sartorii sartorii 



rowly interrupted on the midventral surface. All the San Luis 

 Potosi specimens have complete light rings. Some of the dorsal scales 

 in the light bands are black-tipped in all. In all my specimens the 

 nucha] collar was yellow in life, the remaining light bands red. 



Eventually it may be possible to discern more than one subspecies 

 in this apparently very variable form. The color variants now known, 

 however, do not segregate very well geographically. A specimen with 

 all the annuli complete is recorded by Boulenger (1894, p. 297) from 

 Orizaba, while mine from Potrero has the entire midventral surface 

 black; Boulenger's specimen probably agrees more closely with the 

 San Luis Potosi specimens. My southern snakes show the bands tend- 

 ing toward completeness ventrally, yet the specimen from Guatemala 

 shows the midventral surface entirely black. 



The number of bands seems to be associated with sex. The four 

 females have 15 to 21 body and 5 to 6 caudal bands, while four males 

 have 18 to 22 body and 6 to 8 caudal bands. 



TROPIDODIPSAS SARTORII ANNULATUS (Peters) 



Two specimens were secured, one (No. 109910) from Finca Juarez, 

 Chiapas, the other from La Esperanza, Chiapas (No. 109911). Both 

 were found at night near trails through the forests. 



Two other specimens of this form have been examined, one (No. 

 46436) from Chicharras, Chiapas, the other (No. 12689) from 

 Escuintla, Guatemala. In these four specimens, the supralabials are 

 6-7 in two, 7-7 in two ; infralabials 8-9 in two, 9-9 in one, 9-10 in one ; 

 postoculars 2-2 in all; preoculars 2-2 in two (loreal enters orbit in 

 one of these, passing between preoculars), 1-1 in two; in the two 

 latter, the loreal enters the orbit below the preocular in one, and in the 

 other it enters above the preocular and below a narrow extension of 

 the prefrontals which also enter the orbit. The ventrals are 175, 177, 



