248 BULLETIN 114, UNITED STATES NATIONAL MUSEUM. 



the Davis Mountains, Texas. It answers so closely in structural 

 features to the genus Lampropeltis that, in spite of its unique type 

 of pattern, and lesser structural peculiarities, it must be included 

 here until further specimens make possible a determination of its 

 true status. 



Description. — Since the original description is very accurate it is 

 quoted in entirety : 



Maxillary teeth 13; mandibular 1-^15. Body moderately slender; head distinct, 

 muzzle contracted; eye rather large. Rostral low and broad, barely visible from 



Fig. 78. 



-Lampropeltis alterna (Acad. Nat. Sa., Philadelphia, no. 14977, type, Davis Mounta i.> s» 

 Texas). 2 X nat. size. Showing sttle of color pattern. 



above; intemasals about half the length of prefrontals; frontal a little longer than the 

 suture between parietals, longer than the snout; pariotals large, wide in front, narrow 

 behind; nasals 2, the nostril between them; loreal small, longer than high; preocular 

 1; postoculars, 2 on one side, 3 on the other; temporals, 2+3 on one side, 3+4 on the 

 other; upper labials 7, third and fourth in orbit; lower labials 11. Posterior chin 

 shields a little shorter than the anterior, not separated by scales. Scales smooth, 

 with two inconspicuous pits, in 25 rows. Ventrals 217; anal entire; subcaudals 60 

 pairs. Total length 710 mm. (tail 115). 



The ground color is slate gray, crossed on the back, at intervals of 3 to 5 scales, by 

 bands of black which are alternately wider and narrower, the wide ones covering from 

 2 to 3 scales on the middle of the back, and more or less divided transversely on their 

 centers with scarlet. The narrow bands are about 1 scale wide and wholly black, 

 occasionally broken through by the ground color. On the neck the bands are narrower 



