APPENDIX C. 157 



5. Hcterodon nasicus, B. &G Page Gl 



Specimens of this species vary in the number of small postrostral 

 plates. In some there are only three or four, in others a larger num- 

 ber. Sometimes, instead of a single series of median dorsal spots, 

 there are two, in close contact, and more or less confluent. The nar- 

 row light line across the middle of the superciliaries and the high 

 labials are still highly characteristic. 



Pecos, Tex. 130+1. 40. 23. 14^. 2|. John H. Clark. 



" 141+1. 29. 23. 20*. 2|. " 



« 141+1. 87. 23. 23J. 3^. " 



Eagle Pass, Tex. 144+1. 38. 23. 26^. 3^. Arthur Schott. 



6. Pituoplsis bellona, B. &G Page 66 



Presidio del Norte, Mex. 243.51.32. 51^.6. John H. Clark. 



7. ScotopIliS EsKOl'yijB. &G. — Head rather narrow ; vertical plate 

 elongated. Eye large. Median six or eight scales only carinated ; very 

 slightly. Dorsal rows 29; Above ash-gray, with a dorsal series of trans- 

 verse brown blotches, on each side of which are two others of smaller size ; 

 indistinct traces of a third. A frontal brown vitta passing back through the 

 eye, and crossing the angle of the mouth on to the side of the neck. 



Plates and shape of head much as in S. guttatus. Vertical plate 

 more elongated than in the species of allied color, being decidedly 

 longer than broad. Head rather narrow. Eye larger than in S. 

 guttatus, its centre a little posterior to the junction of the 4th and 

 5th labials. Postorbitals resting on the 5th labial, as in the other 

 species. Anteorbital large. Loral elongated, acute angled behind. 

 Upper labials 8, 6th and 7th largest; lower 11, 6th largest. Dor- 

 sal rows of scales 29, central five or six only carinated, and those 

 only slightly : exterior row largest, rest nearly equal. Ground-color 

 grayish ash. A series of olivaceous brown transverse quadrate 

 blotches along the back, 70 in number, the 50th opposite the anus. 

 These are ten or twelve scales broad, two to three long, and sepa- 

 rated by intervals of one to two scales. They are narrowly margined 

 with black. On each side of the dorsal series, and alternating witli 

 it, is a series of smaller, nearly circular, but similarly constituted 

 blotches extending between the 3d, and 7th or 8th rows : below this, 



