296 PROCEEDINGS OP THE ACADEMY OF 



niscatus, through i s o z o n u s, et. al., and that a belief in the identity of the 

 lemniscatu s with the fulvus will be equally " inevitable." In the case of 

 the forms of the genus Thamnophis, a similar conclusion has been reached, 

 though not consistently carried out, on account of a misapprehension relative 

 to the structure of the preanal plate of the T. sauritus. The admission 

 of the identity of T. s i r t a 1 i s with T. h a y d e n i, renders the acceptation of 

 f a i r e y i and sauritus as distinct from the former, impossible. 



Similar methods of reasoning would necessitate the union of many of the 

 species of Simotes, Tropidonotus, Lampropeltis, Caudisona, and no doubt at 

 some future day of those comprised in the sections of " protean" genera gene- 

 rally. But if we are to be taught by nature, we will not assume a knowledge of 

 her system which we do not possess ; and laying down as our premises 

 what are scarcely yet our conclusions, form associations which a fresh acces- 

 sion of information must compel us to alter. Let us simply record what we 

 find to exist, and while the grand plan becomes more and more evident, will 

 await patiently the period, perhaps not far distant, when we shall fully com- 

 prehend the details of our branch of the great Cosmos, and be able to present 

 it in its completeness to the contemplation of man. 



Elaps euryxanthus Kenn., Proc. Acad. Nat. Sci. Phil. 1860, 337. Mr. 

 Kennicott has not given us the locality whence the specimens described by 

 him were obtained. We believe that one of them was from the region of the 

 Gila. A specimen of the same serpent has been sent to the Mus. Compar. 

 Zoology, Cambridge, from Guaymas, Sonora. 



CoLUBRIDiE. 



Himantodes leucomelas Cope. 



Slender, but less elongated than H. cenchoa. Head very distinct, 

 elliptic. Rostral plate triangular, subinferior. Vertical, with nearly par- 

 allel lateral borders, which are longer than the anterior. Length of occipi- 

 tals, greater than their breadth, and than the vertical ; marginal tem- 

 porals six. Nasals small ; loreal higher than long ; two preoculars, superior 

 not in contact with vertical ; two postoculars, bounded posteriorly by 

 two temporals. Eight superior labials ; eye resting upon the fourth and 

 fifth. Superior labials ten, sixth largest. Seventeen rows of scales, those 

 of the median dorsal broader than long. Length of tail contained three and 

 a half times in the total length. Ground color above and below white tinged 

 with ashy. This is crossed above by twenty-nine black elliptic spots, which 

 cover the tips of the gastrosteges on each side. About eighteen spots on the 

 tail. Beneath, punctulated with black, forming posteriorly a median band. 

 A pair of elongate black spots extend from the posterior half of the superci- 

 liary plates, across part of the vertical, and the whole length of the occipitals, 

 to a short distance posterior to them. They are separated by a narrow band 

 of ground color. There exists a black spot on the anterior part of the vertical, 

 and a band of the same across the postfrontals. 



From Mirador, Vera Cruz. Dr. C. Sartorius. Mus. Smithsonian. 



Himantodes gemmistratus Cope. Himantodes cenchoa Cope, Proc. A. 

 N. S. Phil., 1860, p. 264. 



Similar in proportions to H. cenchoa. Head short, thick, temporal 

 region swollen. Lateral borders of vertical plate slightly convergent, equal 

 in length to the anterior. The special peculiarities which distinguish it from 

 cenchoa are as follows. The scales of the median dorsal series are dia- 

 mond-shaped, longer than broad, not transverse. But one temporal in contact 

 with the postoculars. Sixth inferior labial largest, not the fifth. In colora- 

 tion it is quite similar ; the spots upon the body number about forty-two, but 

 they are peculiar in being connected by a median dorsal vitta. The belly is 

 punctulated laterally, and is without the median vitta of the cenchoa. 



[Sept- 



