NATURAL SCIENCES OF PHILADELPHIA. 343 



Superior labials normally nine, (exceptionally ten,) the fifth, entering the 

 orbit. Inferior labials normally twelve ; geneials two pair, anterior twice the 

 length of the posterior. Tail one-seventh of the total length. Gastrosteges 

 247, an entire anal, urosteges 61. Total length 5 ft. 4 in. Tail 9 in. 



Coloration. The ground color above and below is a rich straw yellow. The 

 muzzle is shaded anteriorly with ashy or fuscous ; this color gradually fades 

 into a lively sanguineous or testaceous, which tint prevails upon the posterior 

 part of the head, and anterior part of the body. There arises upon the tenth 

 or eleventh row of the scales of the neck upon each side, a longitudinal band 

 of the same color, which deepens posteriorly, and unites with its fellow at 

 intervals of three or four scales by a gradual widening upon its dorsal border. 

 Thus a scalariform series of dorsal blotches is formed, whose transverse di- 

 ameter increases regularly posteriorly, and whose intervals diminish, being 

 anteriorly four scales, upon the tail, one and a half. The connecting band 

 remains unbroken upon the anterior fourth of the body only. Separated from 

 this by an interval of one half or a whole scale, another longitudinal and very 

 narrow band arises on the neck. It is much more distinct opposite the inter- 

 vals between the dorsal blotches, and upon the disappearance of the line 

 connecting the latter, partially assumes its position, and breaks up into an 

 alternating series of very elongated spots. The dorsal intervals are thus 

 widened to a breadth of seven and two halves scales. There also commences 

 upon the neck a second lateral series of spots, which occupy a length of five 

 scales on the fourth, fifth and sixth rows. Their length decreases to three scales 

 opposite the anus, where they unite with the superior lateral series. Every 

 second pair of gastrosteges is tipped with sanguineous. All the markings of 

 this serpent are sanguineous anteriorly, but deeper posteriorly, passing through 

 shades of maroon, until upon the terminal third of the total length they are 

 entirely black. A black or maroon band passes along the suture of the uros- 

 teges. Belly immaculate. 



Hah. Cape St. Lucas, Lower California, sent by Mr. John Xantus. Mu- 

 seums Smithsonian, Washington ; Acad. Nat. Sciences, Philada. 



This species will compare favorably for beauty with the elegant Tropidono- 

 tus concinnus of the lamented Dr. Hallowell, but readily yields the paJm 

 to the gorgeous Elaps euryxanthus of Kennicott. 



Ltcodon Boie. 

 Syn, Lycognatkus* Dumeril, Erp. Gen. vii. p. 916. 



L. LYROPHANES Cope. 



In describing this species, I will repeat some of the generic characters, pre- 

 mising that the form belongs probably to the Dipsadinse, to the typical forms 

 of which it is connected by Tripanurgus Fitz. 



Dentition resembling that of Macroprotodon cuoullatus Cope. Seven 

 teeth upon the superior maxillary bone, of which one posterior is elongate 

 and grooved ; three central, small and recurved, and three anterior, very long, 

 the first longest and least recurved. The central three are not separated from 

 those anterior and posterior to them by spaces wider than those existing be- 

 tween themselves. Palatine teeth six, the anterior three the longest, ail 

 longer than the pterygoids. The three anterior mandibular teeth longer and 

 more widely spaced than the posterior, having an outward direction as in 

 Hormonotus Hallow. 



Scales in twenty-one rows, rather broad posteriorly and upon the middle of 

 the body, not larger upon the vertebral line. The body anteriorly is slender, 

 contracting to a small neck. Tail less than one-sixth of the total length. 

 Head very distinct, the temples much swollen, so that the greatest breadth in 

 life is just posterior to the eyes, though the length of head posterior to the 



I860.] 



See my remarks upon this genus, Proc. Phila. Acad. 18tX), p. 262. 



