Eodentia. MAMMALIA. Rodentia. xcvii 
TOWNSEND’S MEADOW MOUSE (A. (Myonomes) 
townsendi, Bach.) — 'I’liis is a niucli lar^ei’ species 
thiui the preceding', measui'iiig' five to six indies in 
lengtli. ’J’iie tail is longer in proportion ; and the 
ears are also rather larger. 'I’he vvliiskers are about 
as long as the head. The soles of the feet, like those 
of riparius, have si.x tubercles. In color, it is nearly 
like the preceding. Some doubt is expressed about 
the validity of tlie species, and it may prove to be 
only a variety of the A. riparius. 
A variety called A. riparius, variety horealis, Rich- 
ardson, is the Litti.e Northern Meadow Mouse, 
found in North-western America. It is a little smaller 
tiian the former, witli smaller ears and feet, both be- 
ing more hairy. 
CHESTNUT-CHEEKED MEADOW MOUSE (A. [ilyo.) 
xanthognathus, Leach). — Found in North America, 
north of the United States. “ It is one of the largest 
of the American Arricolm we have ever handled. It 
measured six and a half inches long wlien fresh, and 
the skin indicates, a stout bulky animal.” 'I’he 
tail is shorter in jiroportion than in riparius. 'I’he 
specific name indicates “yellow-cheeked,” but its 
color in the region of the cheeks is a bright bay or 
chestnut. 
THE LARGE NORTHERN MEADOW MOUSE {A. 
richnrdsoni. And. and Bach.) is a variety recorded 
by Dr. Coues as doubtful. It is the same as ap- 
pears in DeKiiy’s Report on the Mammals of New 
York. 
Sub-Genus— C mr.OTUS. — Baird. 
'I’his genus is characterized by very small form, 
with small and orbicular ears (hence the name, lip- 
eared — Cheilos. a lip, and otus, ear); the marginal 
portion, or helix, incurved all around. 'I'lie surfaces 
of the ear are almost naked. 
OREGON MEADOW MOUSE [A. {Ghilotus) oregonus, 
Bach.) — 'I’his is said to resemble a half-grown A. 
riparius at first sight, but examination shows readily 
that it is adult. It is from the Pacific Coast. 
Sub-Genus — ^Pedomys. — Baird. 
'I’he ears in this sub-genus have not the inflected 
margin of the preceding, but are concealed. 'I'lie 
plantar tubercles are only five. 
PRAIRIE MEADOW MOUSE (A. [Fedomys) austerus, 
LeGonte.) — This inhabits the Western States and ad- 
joining territories, and south to Louisiana. 
WESTERN PRAIRIE MOUSE {A. {Fedomys) curt- 
atus. Gope). — This is found in the States west of the 
Mississippi. The tail is shorter than the head ; color 
of the 'body a brownish-gray ; size about four inches 
in length. 
Sub-Genus — Pitvmys. — McMurt. 
'I'his is below medium size. 'I'he body is cylindri- 
cal, and Shrew-like in various features. 'J’he tail is 
very short; the ears small and nearly concealed, 
sparsely pilose, with flat edges, the border of meatus 
plain in front. The term of the sub-genus is from 
the Greek — pitus. pine; hence. Pine-mouse. 
VoL. l .—n. 
PINE MOUSE [A. {Fitymys) pinetorum, I^eGontd). 
— This is a small Mouse, resembling a .Mole, with 
close silky fur. 'J’he tail is shorter than the head. 
The hind-feet are small, with only five tubercles. 
The fore-feet are comparatively large. 'I’he ears are 
small, flat and round, with little hair, and nearly con- 
cealed in the fur. It inhabits the United States 
east of the Mississippi. 
Aroicola [Fitymys] quasiater, Goues). — In general 
form and appe;irance this is like A. pinetorum. It is 
named as above from the seemingly black aspect of the 
fur, which, on closer inspection, however, is found to 
be of an auburn shade. This species is from Mexico. 
Synaptohys. — Baird. 
This is regarded as one of the most strongly 
marked genera of American Maridm. “ The most 
cons])icuou3 and diagnostic character, if not really 
the most important, is the sulcation of the upper in- 
cisors. It is a unique feature among American Arvi- 
colinm, if not in the sub-family ; and, in the American 
representative of the whole family Muridce, only 
recurs in Ochetodon of North and Reithrodon of 
South America. 'I’he groove runs near the outer 
edge of the face of the tooth. In Ochetodon and 
Reithrodon it is median.” 
COOPER’S MOUSE [Synagdomys cooperi, Baird .) — 
'Phis form is found in Indiana and Illinois, and west 
to Oregon and A laska. Prof. Baird named this species 
from an imperfect specimen, the only one that could 
be obtained at the time. Dr. Coues has since re- 
ceived a number from Kansjis, which fully answer to 
the characters recorded, Synaptomys being substi- 
tuted for Myodes and Arvicola. 
Myodes. — Fallas. 
'I’he skull in this genus is massive, low and broad ; 
the width of the zygoma neai ly two thirds its length. 
'I’he molar series is long — more than one fourth the 
length of the skull — very convergent anteriorly ; and 
the teeth are each very large. 'I’lie details of the 
crowns of the teeth are like those of the preceding. 
The first upper and under molars are the longest. 
'I’he Myodes are large, and have a long, thick pelage. 
The snout is blunt, covered with hair, excepting the 
nasal papillae. 'I’he ears are small and concealed. 
The fore-feet are large ; there is no thumb. 
Myodes obensis, Brants. — This has a form closely 
like that of the Norway Lemming. It is found in 
Asia, as well as Western America. 
CuNicuLUS. — Wagler. 
'I’his genus is characterized by a skull lower and 
broader and more massive than in Arvicola, and 
somewhat less so than in IMyodes. 'I’lie zygoma is 
not two thirds the length. In general characters it 
resembles the preceding. Some dental peculiarities 
are recorded. 
COLLARED LEMMING [Guniculus torquatus, {Fall.) 
Goues). — ^This form is the only one of the genus in 
America, and it is indentical with that of Northern 
Asia. 'I’he Cree Indians call it “ White Bear Mouse ;” 
Pennant, the Hudson’s Rat, and Hair-tailed Rat; 
