68 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
M. De Saussure has been more fortunate in handling Mexican Hesperomys 
than be was in this case, for one of these specimens is an adult and the other 
a young example of deucopus; neither of them shows the slightest departure 
from the ordinary type. We have not met with either of these names in 
print, and if, indeed, they were never published, we shall regret their appear- 
ance on our page; for a synonym once rooted is hard to eradicate. 
Now, passing over for a moment a certain Eastern United States variety 
of Zeucopus that we shall be prepared to establish farther on, and likewise post- 
poning consideration of the names ‘‘cognatus” and “maniculatus”, as these 
are best treated in connection with var. gossypinus, we will examine several 
western names that we claim have no foundation. 
The first western ‘‘species” (so-called) that we shall notice, is Hesperomys 
“texanus” of Woodhouse (type, No. 2559, Mus. Smiths., in alcohol, from 
Western Texas). The author’s description shows nothing whatever different 
from ordinary /eucopus, except small size (length, 2.10; tail the same); but 
this, of course, is matched by any other ungrown /eucopus. he character, 
“legs white on their inner surface only” (¢. e., color of back extending over 
outside of legs), is not of the slightest consequence, since plenty of typical 
leucopus show it, especially immature ones. In admitting the species, which 
he places next to dewcopus, Professor Baird found it ‘‘very difficult to charac- 
terize it as distinct from /eucopus, although it is very probable that the two are 
distinct.” He assigns “size and proportions about as in /eucopus ;” 
and his 
table of measurements does not show any discrepancy. The ears are not 
smaller, as given by both these authors. We fail to appreciate any distinction 
in color, except a slight average paleness ; and for this we shall be abundantly 
prepared after we have looked up var. sonoriensis. Finally, we tabulate the 
several specimens that have been referred to texanus ; it is the more surpris- 
ing that Dr. Woodhouse should have described his specimen as distinct, since 
he was well acquainted with deucopus, which, as he says, is “common in the 
Indian Territory and Texas.” 
