50 
REPORT ON ZOOLOGY, MDCCCXLII : 
himself, has at present only said that the tail of the latter is somewhat 
larger than that of the former : both species are natives of Columbia 
river. 
Murina. — Waterhouse has made a modification in the 
arrangement of this family, in the Ann. x. p. 203, after the 
following scheme : — 
Family. — Murids — Genera: Gerhillus, Psammomys, Miis, Hespe- 
romys, Dendromys, Phlceomys, Cricetomys, Cricetus, Euryotis, Hapa- 
lotis, Reithrodon, Sigmodon, and Neotoma. 
Sub -family 1. — Aspalomyina — Genera: Rhizomys, Aspalomys, 
(Spalax), and Heterocephalus. 
Sub -family 2. — Arvicolina — Genera: Ondatra, Arvicola, and 
Lenimus. 
Against this arrangement the reporter has to observe, that its logical 
sequence is not to be granted, as the two sub-families, taken together, 
do not, perhaps, form a part of the family Mxiridce, but stand as an 
appendix to it. This appendix, moreover, would not be necessary for 
the ArvicolcB, as they, in the most essential respects, bear the type of 
the Mice, and in their most important difference, the construction of the 
molars, do not stand isolated, but by Neotoma and Mystromys, advance 
into very intimate union with the other divisions of the Murince. It is 
somewhat different with the Aspalomyina, These are strange members 
in the family of the Mice, varying from them very essentially in the 
structure of the skull, the molars, and cutting teeth, and in the limbs, so 
that the passage from them to the Mice is only made by a jump. My 
arrangement and division of the family Murina is now completed in 
Schreber’s Suppl. iii. 
Two new genera have been described by Gray in the Ann. x. p. 264, 
Nesokia and Vandeleuria. On their relation to the other genera, the 
reporter does not venture any judgment, as the present description is 
not sufficient for that purpose. The molars even of Vandeleuria are 
not known. Nesokia. — Cutting teeth very large, flat in front and 
smooth ; grinders | ; front, in upper jaw, large with three cross ridges ; 
the middle oblong, and the hinder much narrowed behind, each with 
two cross ridges ; the front lower grinder larger, narrowed in front with 
three cross ridges ; hinder each with two ridges, the hindermost smallest ; 
tail short, thick, with whorls of scales and scattered bristles ; ears 
moderate, naked. The author distinguishes this genus from Mus, by 
the large cutting teeth and short tail; he looks on it as intermediate 
between Mus and Rhizomys. As a species, he places in it Mus Hard- 
wicMi from India ; and he thinks it probable that Brandt’s Hypudceus 
Guira may belong to the genus. Vandeleuria. — Upper cutting teeth 
triangular, with a deep groove near the middle on the oblique front 
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