758 The American Naturalist. [ August, 
I. One frontal and frontonasal plates. 
Superciliary scales, none ; pupil round, Lepidophyma Dum. 
Superciliary scales present ; pupil erect, Xantusia Bd. 
II. One frontal and two frontonasal plates, pupil erect. 
An interoccipital plate ; frontoparietals i in contact; superciliaries, 
Zablepsis Cope. 
No interoccipital ; frontoparietals widely separated ; superciliaries, 
Cricosaura Pet. 
III. Two frontals and one frontonasal; pupil erect. 
No interoccipital ; frontoparietals in contact; superciliaries, 
Amebopsis Cope. 
Each genus includes but one species except Xantusia, which has 
two. The type of Zablepsis is the Xantusia henshavii Stejneger, and 
the type of Amcebopsis is X. gilbertii Van Denburgh. The former is 
from Southern, the latter from Lower California—E. D. Cope. 
Occurrence of the Siberian Lemning-Vole (Lagurus) in 
the United States.—In describing a new vole (Arvicola pallidus) 
from Dakota, in 1888, I referred it to the subgenus Chilotus of 
Baird, with which it agrees in the number of triangles in the molar 
teeth. Two years later, when studying a collection of voles from 
Idaho, I found that pallidus and its near ally pauperrimus, differed 
from Chilotus in important cranial and external characters, and 
the teeth, while agreeing in the number of triangles, differed 
materially in other respects. They were, therefore, removed from 
Chilotus,’ but a new subgenus was not erected for them because it was 
believed that they would be found to fit into some of the numerous 
named groups of Eurasian voles of which no specimens were then avail- 
able for comparison. Through the courtesy of Mr. Gerrit S. Miller, 
Jr., I now have before me a skin and skull of the Siberian Lagurus 
lagurus (Pallas) [== Eremiomys lagurus Auct.*], collected at Gurjew on 
the north shore of the Caspian Sea, and recently received by him from 
1 AMERICAN NATURALIST, August, 1888, 702-705. | : 
2N. Am. Fauna, No. 5, August, 1891, 64-65. 
° The generic name, Lagurus, of Gloger (1841), antedates Hremiomys Poliokoff 
(1881) by forty years. For an article on Gloger’s names see Thomas, in Apa 
and Magazine Nat. Hist., Ser. 6, Vol. XV, 1895, pp. 189-193. 
