932 REPORT OF NATIONAL MUSEUM, 1898. 



on the four or five central rows of scales, whence to the flanks it is 

 varied by having the centers of each scale reddish yellow. The inter- 

 vals between the blotches are exactly the reverse; above they are uni- 

 form pale red, and on the sides the centers of each scale are black. 

 Sometimes scattered black scales may be observed on the back in the 

 light spaces. Beneath yellowish white, unspotted. The two outer 

 rows of scales of the same color, but with a short black bar extending 

 from the middle of each light and each dark space, perpendicularly to 

 the abdomen, the extreme edge of which is sometimes involved. The 

 head and half its length behind are black, spotted with yellowish on 

 the sides. The snout and labials yellowish, the plates margined with 

 black. 



Cat. Nos. Upper labials. Gastrosteges. Urosteges. Scales. Length. Tall. 



')n7n. mm. 



4472 8. 199 + 1. 50. 23. 732. 109. 



8621 8. 212 + 1. 51. 23. 295. 41. 



2016 8. 207 + 1. 46. 23. 585. 78. 



This species displays remarkable variations in coloration. In Cat. No. 

 5168 the large blotches are perfectly distinct, and their lateral inter- 

 spaces have but faint traces of markings. In Cat. Nos. 20i:u, 2()2o, 20.')0, 

 2031, 11743, 11784, all of small size, and Cat. No. 2010, fully grown, there 

 is a vertical black spot between the dorsal blotches on each side. In 

 Cat. Nos. 8370, 4471, 4472 the entire space on the sides between the dorsal 

 blotches is marked with a black spot ou the center of each scale. Cat. 

 Nos. 8021 and 8022 are more like the first noted variety, but carry the 

 peculiarity further. The dorsal blotches are perfectly distinct from 

 each other and are truncate, and not narrowed at their inferior border. 

 Very few of the scales have light centers, and there are no intermediate 

 lateral spots. Belly spots sparse. In Cat. No. 8022 a wide longitudinal 

 median black band forms, with the occipital spot, an anchor-shaped 

 figure. This variety is approached nearly by the second and only other 

 species of the genus, the R. antonii Duges, which has the black cross 

 bands fewer in number and wider. It is from Mazatlan. Individuals 

 also ditfer in the relative size of the loreal plate and number of cross- 

 bars. In one from the Canadian River there are thirty seven rings; 

 in one from the Llano Estacado twenty six. In another from the same 

 locality the abdomen is black, tessellated; in all others, white. 



The range of the Rh'mochUus lecontei is throughout the Sonoran dis- 

 trict. The most eastern and northern locality known for it is G-arden 

 City, in southwestern Kansas, where Professor Cragin, of Topeka, 

 obtained a specimen. It presents the anomaly of having the loreal 

 plate to enter the orbit below the preocular. 



Mr. S. W. Garman' names a "var. tessellatus,^^ with the sole descrip- 

 tion: "Labials, eight. Infralabials, ten. Ventrals, one hundred and 

 seventy-eight. Subcaudals, thirty-seven entire, plus fourteen pair.'' 



' Mem. Mus. Comp. Zool., VIII, 1883, p. 74. 



