OPHIDIA— COLUBKIDAE— TK1MOKPHODON LYROPHANES. (521 



63. Trimorphodon lyrophanes, Cope. 



Lycodon lyrophanes, Cope, Proc. Acad. Nat. Sci. Phila., 1860, 343. 



Trimorphodon lyrophanes, Cope, Proc, Acad. Nat. Sci. Phila., 1866, 310. — Id., Check- 

 List, 1875, 38. 



Scales in 21 rows, broad posteriorly and upon the middle of the body, 

 the dorsal series not larger ; body anteriorly slender ; neck contracted. Tail 

 not one-sixth the total length. Head broadest just behind the eyes ; con- 

 stricted at the orbits. Muzzle rather narrow and truncate. Rostral broader 

 than high, with four sutural borders : the superior one very long ; the apex 

 apparent upon the surface of the head. Prefrontals much broader than long ; 

 one-third the size of that part of the postfrontals visible from above. Post- 

 frontals longer than broad upon vertical view. Occipitals, superciliaries, and 

 vertical well developed ; the last right-angled posteriorly, with slightly con- 

 cave and convergent lateral borders. Occipitals not longer than vertical ; 

 about as wide as long- : in contact with a large scale in their posterior com- 

 mon emargination. Nasal plates distinctly divided, very small, higher than 

 long. Loreals two ; anterior one higher than long, wedged above between 

 pre- and postfrontal ; the posterior as long as high. Preoculars three; the 

 superior largest, not in contact with the vertical ; the inferior bounded an- 

 teriorly by the third upper labial. Postoculars tln-ee ; the inferior a little the 

 largest, Superior labials nine ; fourth and fifth entering the orbit, sixth 

 largest, higher than broad. Inferior labials twelve, third and fourth narrow, 

 and much produced posteriorly. Geneials two pair, the anterior longest. 

 Gastrosteges, 236; one divided anal; urosteges, 70. Length, 27 inches 10 

 lines ; tail, 4 inches -1 lines. Ground color light-gray. Muzzle crossed by 

 an indistinct ashy band, which extends upon the anterior part of the post- 

 frontals. The posterior half of these plates is involved in a deep-brown 

 band across the head between the eves, with concave posterior border, ex- 

 tending upon the superciliaries, and continued posteriorly upon the inferior 

 postorbital and sixth upper labial. A pair of broad diverging bands, com- 

 mencing one on either side of the center of the vertical, crosses the super- 

 ciliary and occipital, follows the expanded outline of the temporal and tym- 

 panic regions, contracts and becomes parallel and longitudinal upon the neck. 

 A brown spot upon the posterior extremity of the verticals, with its posterior 



