NATURAL SCIENCES OP PHILADELPHIA. 337 



long, and usually there are just behind it two contiguous plates of about the 

 same size separating it from the postfrontal, but not from the prefrontal. 

 Frequently, however, the azygos is longitudinally divided and without any 

 additional plates, but in contact with the rostral anteriorly, and the vertical 

 posteriorly, and not separated from the postfrontals. The vertical, occipital?, 

 superciliaries and labials are much as in H. n a s i c u s , though generally 

 less developed longitudinally. The rostral is as large as in H. nasicus. 

 The two outer dorsal rows are both perfectly smooth ; inH. nasicus, the 

 second is distinctly though delicately carinate. 



The ground color is light yellowish gray, with a dorsal series of rather in- 

 distinct subquadrate or rounded blotches, two to two and a half scales long, 

 and separated by intervals of one or two scales, rather wider anteriorly. Be- 

 low this is a series of very distinct purplish black circular blotches, covering 

 four scales transversely and two longitudinally ; below this, one or more in- 

 distinct series of spots. This pattern of coloration is very similar to that of 

 H. nasicus, but the ground color is always lighter, and the dorsal spots 

 are lighter and less distinct. The upper lateral series is of a purplish black, 

 and much more distinct, forming a prominent character. 



Abdomen nearly entirely black, except a few yellow scuta. The head is 

 marked as in H. n a s i c u s , except that the nasals, prefrontals and rostral 

 are all yellowish, while in the latter species they are dark in front of the light 

 transverse line which crosses the crown behind the rostral ; and in H. 

 Kennerlyi the light line across the superciliaries and vertical is much 

 broader than in H. n a s i c u s. This species differs from H. s i m u s in many 

 of the same features as does H. nasicus. These, together with the small 

 or absent loral, and small number of supplemental plates, will readily distin- 

 guish it. 



Rio Grande. Dr. Kennerly. 



Sonora. 



ELAPS Schneider. 



Elaps EURYXANTHr/s Kennicott. 



Spec. char. Head very small, narrower than the neck ; entirely black as 

 far back as the angles of the mouth. Body banded alternately with black 

 and light brick red, separated by narrow rings of creamy white, all the brands 

 immaculate. First broad ring behind the occiput red instead of black as in 

 the other species. 



Descr. Body rather stout, but less so than in E. f u 1 v i u s . Dorsal scale 

 large. Plates of the head small except the rostral, which is very large and 

 extends upward between the prefrontals. Prefrontals elongated laterally, more 

 so than in E. t e n e r . Post frontals small, elongated laterally ; vertical very 

 small and narrow, subhexagonal, pointed anteriorly, elongated and tapering 

 posteriorly; it enters but slightly between the occipitals. Occipitals small, sub- 

 triangular, the anterior edge square, very slightly notched for the vertical. 

 Seven labials above ; posterior very small. 



The fore part of the head is black, but the black instead of passing forward 

 from the anterior part of the occipitals to near the eye, and thus leaving the 

 three posterior labials yellow as in E. f u 1 v i u s and E. t e n e r , involves 

 nearly the whole of the occipitals, and passes backward entirely behind the 

 angle of the mouth and involves the whole of the lower jaw to behind the 

 posterior labial, leaving a broad emargination in the black on the occiput in 

 the bottom of which emargination are seen the white posterior tips of the 

 occipitals. Behind this is a creamy white ring, (probably yellow in life) which 

 is situated more posteriorly than inE. fulvius, and in vol ves only the posterior 

 tips of the occipitals and none of the labials. Next behind this white ring, instead 

 of a black ring, as in the other species, is a broad light brick red one involv- 

 ing eleven scales. A creamy white ring three and a half scales wide sepa- 

 1860.J 



