OPHIDIA COLUBRIDAE TJ41MOKPHODON LYROPHANES. 621 



63. Trimorphodon lyrophanes, Cope. 



Lycodon Jyrophanes, 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 three ; 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 4 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 eyes, with concave posterior border, ex- 

 tending upon the superciliaries, and continued posteriorly upon the inferior 

 postorbital and sixth iipper 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 



