162 PROCEEDINGS OF THE NATIONAL MUSEUM vol. m 



covering about three-fourths as many scale lengths laterally as on 

 middorsal line; each dark band with a narrow, broken, transverse 

 white line dividing it into two halves; spaces between bands white, 

 covering one and one-half to two and one-half scale lengths medially, 

 all except the anterior three and nuchal collar enclosing laterally a 

 small dark spot, which involves two scales of the first scale row and 

 the end of the ventral scale between them; dark bands encroaching 

 on ventral surface, the median and posterior completely encircling 

 body, although with numerous light flecks on midventral surface; 

 numerous dark flecks on venter between posterior bands; ventral 

 surface of tail irregularly mottled with light and dark; chin 

 immaculate. 



Comparisons. — This species most closely approaches latifascia 

 Peters, as defined by the specimens reported by Taylor.^ One of 

 these is described as having the first four bands covering 19, 15, 16, 

 16 scales (first five covering 19 to 21 in fasciolata), but they are 

 distinctly narrower laterally, involving 7 to 9 ventrals, while the 

 white areas between involve 9 or 10 (dark bands involve 13 to IT, 

 light bands 6 ventrals in fasciolata) . 



TRIMORPHODON UPSILON Cope 



Trimorphodon upsilon Cope, Proc. Amer. Philos. Soc, vol. 11, p. 152, 1869 (Guada- 

 lajara ; type, U.S.N.M. No. 3135S ) .—Taylor, Kansas Univ. Sci. Bull., vol. 

 25, pp. 365-366, pi. 35, fig. 2, 1938 (1939). 



Diagnosis. — ^A light, transverse nuchal collar; head largely dark, 

 but with a light interocular bar and a Y-shaped light mark on parietal 

 region, the arms of which fork immediately behind frontal ; 23 to 32 

 body blotches, 11 to 15 tail blotches. 



Specimens examined. — Twelve. 



Locality records. — Known from the central, southern, and north- 

 western plateau region. Recorded from the States of Chihuahua 

 (Batopilas), Durango (Ventanas) ; Guanajuato; Hidalgo (Zacual- 

 tipan; 10 km. north of Jacala) ; Jalisco (Cumbre de los Arrastrados; 

 Guadalajara; Magdalena) ; Michoacan (Tacicuaro) ; Nayarit (Sierra 

 de Nayarit) ; Zacatecas (San Juan Capistrano). 



Remarks. — The dorsal bands of a specimen observed in life (from 

 Magdalena, Jalisco) were reddish brown; the color and general char- 

 acter of the rhombs resembled to some extent those of certain Lam- 

 propeltis. 



The ventral surface in this species is distinctly marked with ir- 

 regular black spots; the subcaudal surface is more heavily blotched 

 than the belly. A single exception is a somewhat faded, soft speci- 



» Kansas Univ. Sci. Bull., vol. 25, pp. 364-365, pi. 36, fig. 2, 1939 ; vol. 26, p. 479, pi. 52, 

 1940. i 



