MUS MISSOURIENSIS.--Aud.and Bach.
                             [Microtus ochrogaster]

                                MISSOURI MOUSE.
                                 [Prairie Vole]

                               PLATE C.--FEMALES.


     M. capite amplo, cruribus robustis, auriculis sub albidis, cauda curta,
corpore supra dilute fusca, infra alba.

                                CHARACTERS.

     Head, broad; legs, stout; ears, whitish; tail, short, light fawn colour
above, white beneath.


                                   SYNONYME.

     MUS MISSOURIENSIS, Aud. and Bach., Quads. North America, vol. 2, plates,
       pl. 100.


                                  DESCRIPTION.

     At first sight we might be tempted to regard this animal, as one of the
endless varieties of the white-footed mouse.  It is, however, a very different
species, and when examined in detail, it will be discovered that the colour is
the only point of resemblance.  The body is stouter, shorter, and has a more
clumsy appearance.  The nose is less pointed; ears, much shorter and more
rounded; and the tail, not one-third of the length.
     Head, short and blunt; nose, pointed; eyes, large; ears, short, broad at
base and round, sparsely clothed with short hairs on both surfaces; moustaches,
numerous, long, bending forwards and upwards; legs, stout; four toes on the
fore-feet, with the rudiment of a thumb, protected by a conspicuous nail; nails,
rather long, slightly bent, but not hooked.  The hind-feet are pendactylous; the
palms are naked; the other portions of the feet and toes, covered with short
hairs, which do not, however, conceal the nails.  The tail is short, round,
stout at base, gradually diminishing to a point; it is densely covered with
very short hair; the fur on both surfaces is short, soft and fine.


                                   COLOUR.

     Teeth, yellowish; whiskers, nearly all white, a few black hairs
interspersed.  The fur on the back is plumbeous at the roots to near the points,
the hairs on the sides are broadly tipped with yellowish-fawn, and on the back,
are first fawn, and then slightly tipped with black; on the under surface, the
hairs are at the roots plumbeous, broadly tipped with white.  The ears are
nearly white, having a slight tinge of buff on the outer and inner surfaces,
edged with pure white; on the sides of the cheeks, and an irregular and
indistinct line along the sides, the colours are brighter than those on the
flanks, and may be described as light yellowish-brown.  The feet, on both
surfaces, belly, and under surface of tail, white; from this admixture, this
species is on the back, light fawn, with an indistinct line on the back, and
upper surface of tail, of a shade darker colour.


                                  DIMENSIONS.

                                                        Inches.

     From point of nose to root of tail, .  .  .  .  .  4 1/2
     From point of tail,  .  .  .  .  .  .  .  .  .  .  1 1/8
     Height of ear, posteriorly,.  .  .  .  .  .  .  .    3/8


                                    HABITS.

     We close our second volume with this new species of mouse, of which we have
given three figures.  This pretty little animal was discovered for us by Mr.
DENIG, during our sojourn at, and in the neighbourhood of Fort Union in 1843.
It was in full summer pelage, having been killed on the 14th of July.  At that
time being in quest of antelopes and large animals, we did not give it that
close attention, which we should have done.  A glance at our plate, or an
examination of our description, will suffice to convince any one of its being
entirely new.  This species is much larger, and has a thicker and shorter tail
than mus leucopus.
     Expecting to get more of them we did not make any notes of the habits of
those killed at that time, and which had doubtless been observed by the hunters,
who procured them.  The next day after they were brought in, we left the fort on
an expedition to the Yellow-Stone river, from which we did not return for some
time.
     As a short description of our mode of travelling, &c., the first day's
journal is here given. "July 15, Saturday, we were all up pretty early, making
preparations for our trip to the Yellow-Stone river.  After breakfast all the
party who were going, announced themselves as ready, and with a wagon, a cart,
and two extra men from the fort, we crossed the Missouri, and at 7 o'clock, were
fairly under way; HARRIS, BELL, CULBERTSON, and ourself in the wagon, SQUIRES,
PROVOST, and OWEN on horseback, while the cart brought a skiff, to be launched
on the Yellow-Stone, when we should arrive at that river.  We travelled rather
slowly until we had crossed a point and headed the ponds on the prairie at the
foot of the hills opposite the fort.  We saw one sharp-tailed grouse, but
although Mr. HARRIS searched for it diligently, it could not be started.  Soon
after this we got one of the wheels of our wagon fast in a crack or crevice in
the ground, and wrenched it so badly that we were obliged to get out and walk,
while the men set to work to repair the wheels which were all in a rickety
condition; after the needful fixing-up had been done, the wagon overtook us, and
we proceeded on.  Saw some antelopes on the prairie, and many more on the tops
of the hills bounding our view to the westward.  We stopped to water the horses
at a "saline," where we observed that buffaloes, antelopes, and other animals
had been to drink, and had been lying down on the margin.  The water was too hot
for us to drink.  After sitting for nearly an hour to allow the horses to get
cool enough to take a bait, for it was very warm, we again proceeded on until
we came to the bed of a stream, which during spring overflows its banks, but now
exhibits only pools of water here and there.  In one of these pools we soaked
our dry wagon wheels, by way of tightening the "tires," and here we refreshed
ourselves and quenched our thirst.  SQUIRES, PROVOST, and OWEN, started on
before us to reconnoitre, and we followed at a pretty good pace, as the prairie
was hereabouts firm and tolerably smooth.  Shot a red-wined black-bird.  Heard
the notes of NUTTALL's short-billed marsh-wren,--supposed by some of our party
to be those of a new bird.  Saw nothing else; reached our camping-place at about
6 o'clock.  Unloaded the wagon and cart, hobbled the horses, and turned them out
to grass.  Two or three of the men went off to a point above our camp, in search
of something for supper.  We took the red-wined black-bird, and a fishing-line,
and went to the bank of the famed Yellow-Stone river, (near the margin of which
our tent was pitched,) and in this stream of the far west, running from the
bases of the Rocky Mountains, we threw our line, and exercised our piscatory
skill so successfully as to catch some cat fish.  These fish we found would not
bite at pieces of their own kind, with which we tried them; after expending our
bird bait, we therefore gave up fishing.  One of our men took a bath, while two
others, having launched the skiff rowed across the river to seek for deer or
other game on the opposite shore.  Toward dark the hunting parties all returned
to camp without success; and we found the cat-fish the principal portion of our
supper, having no fresh meat at all.
     Our supper over, all parties shortly disposed themselves to sleep as they
best could.  About 10 o'clock, we were all disturbed by a violent thunder storm,
accompanied by torrents of rain and vivid flashes of lightning; the wind arose
and blew a gale; all of us were afoot in a few moments, and amid some confusion,
our guns, loaded with ball, and our ammunition, were placed under the best
covering we could provide, our beds huddled together under the tent along with
them, and some of us crawled in on top of all, while others sought shelter under
the shelving bank of the river.  This storm benefitted us, however, by driving
before the gale the mosquitoes, to keep off which we had in vain made a large
fire, before we laid ourselves down for the night."
     As there is little grain of any kind grown in this part of the country, the
Missouri Mouse no doubt exists on the seeds and roots of wild plants entirely,
of which it is able to lay up a store for the winter in holes in the ground.  It
may, however, possibly resort to the patches of corn planted by the squaws of
some of the Indian tribes, at the time that grain is ripe.  We brought with us
from this country, when we returned home, some ears of a very small corn,
(maize,) which ripens early, and bears its fruit near the ground.  Having
planted it on our place, we found that it was advanced enough to be eaten at
table as a vegetable, several weeks before the ordinary kinds of corn known
about New-York.  We, therefore, distributed some of the seed among our farming
neighbours, and likewise sent some to England to Lord DERBY and other friends,
but this was unfortunately lost.  We incline to believe that this corn would
ripen well in the climate of England or Scotland.  Unluckily, ours has become
ruined by having been planted too near common corn, and is now depreciated or
reduced to nearly the same thing as the latter.


                           GEOGRAPHICAL DISTRIBUTION.

     This species was discovered in the State of Missouri.


                                GENERAL REMARKS.

     The Missouri Mouse bears some resemblance to the common and very widely
distributed White-footed Mouse.  Its comparatively heavy and clumsy form--its
large head and short tail have induced us to regard it as a distinct species.
eIn the mice, shrews, and bats, we have no doubt several interesting species will
yet be detected in our country.