SPERMOPHILUS ANNULATUS.--Aud. and Bach.
                            [Spermophils franklinii]


                         [Franklin's Ground Squirrel]


                              PLATE LXXIX.--MALE.


     S. Super cervinus, pilis nigris, interspersis, subtus albido.  Cauda
corpore longiore, annulis, 17-20 nigris.

                                CHARACTERS.

     Reddish-brown above, speckled with black beneath.  Tail, which is longer
than the body, annulated, with from seventeen to twenty black bands.


                                   SYNONYME.

     SPERMOPHILUS ANNULATUS.  Aud. & Bach.  Transactions of the Academy of
       Natural Sciences, Oct. 5th, 1841.


                                  DESCRIPTION.

     In size, this species is scarcely larger than the Hudson's Bay Squirrel,
(S. Hudsonius.)  In the shape of the head it resembles Spermophilus Parryi.  The
ears are quite small, being scarcely visible above its short coat of rather
coarse, adpressed hairs; they are thickly covered with hair on both surfaces.
The nose is sharp; whiskers, (which are numerous,) the length of the head.  Eyes
of moderate size, situated on the sides of the head.  The os-frontis is rounded
between the orbits, as in S. Franklinii.  The cheek pouches are pretty large,
and open into the mouth immediately anterior to the grinders.  The body is more
slender than the spermophiles in general, and in this, and several other
peculiarities which will be mentioned, this species approaches the genus
Sciurus.  On the fore-foot, a sharp, conical nail is inserted on the tubercle
which represents the thumb.  There are four toes, covered to the extremities
with a close, smooth coat of hair.  The first and the fourth toe are of equal
length.  The second and third, which are longest, are also uniform in length.
The nails are short, crooked and sharp, like those of the Squirrels, and not
like those of the Marmots and Spermophili in general, which are long and
slender, and but slightly curved.  The legs are long and slender.  The hair on
the back is rather short, and lies close and smooth.  The short fur beneath this
coarser hair is rather sparingly distributed, On the under surface, the hairs
are longer, and so thinly and loosely scattered as to leave the skin visible in
many places, especially on the abdomen, and inner surface of the thighs.  The
hind feet, which are thickly covered with short, smooth hairs, have five toes.
The soles, as well as palms, are naked.  The tail, by its great length and
singular markings, presents a distinguishing peculiarity in this species; it is
flattened, and the hairs admit of a distichous arrangement; but the tail is
narrower, and less bushy than those of the Squirrels.


                                    COLOUR.

     The incisors are deep orange; nails, brown; whiskers, black; nose and
sides of the face, chestnut-brown.  There is a line of soiled white above and
around the eyes.  The hairs on the upper surface are yellowish-brown at the
roots, barred about the middle with black; then another line of yellowish-brown
and tipped with black, giving it a dark, greyish-brown, and in some lights a
speckled appearance.  The small spots are, however, no where well defined; upper
surface of the feet and legs, yellowish-brown; the under parts, chin, throat,
belly, and inner surface of the legs and thighs are white.  The tail is
annulated with about nineteen black, and the same number of cream-coloured
bands, giving it a very conspicuous appearance.  These annulations commence
about three inches from the root of the tail, and continue to be well defined
till near the extremity, where the colours become more blended, and the rings
are scarcely visible.  On the under surface, the tail is pale reddish-brown,
irregularly, and not very distinctly barred with black.


                                  DIMENSIONS.

                                                       Inches.   Lines
     Length from point of nose to root of tail,  .  .  .  8       2
     Length of tail vertebra,  .  .  .  .  .  .  .  .  .  8       0
     Length to end of hair, .  .  .  .  .  .  .  .  .  .  9       4
     From heel to end of middle hind claw, .  .  .  .  .  1      10
     Height of ear, posteriorly,  .  .  .  .  .  .  .  .  0       1 1/2
     Length of longest fore-claw, .  .  .  .  .  .  .  .  0       2
     Length of longest hind claw, .  .  .  .  .  .  .  .  0       2 1/2


                                    HABITS.

     We possess no knowledge of the habits of this species, but presume from its
form, that it possesses the burrowing propensities of the genus.  All the
Spermophili avoid thickly wooded countries, and are either found in rocky
localities, or burrowing in the prairies.


                           GEOGRAPHICAL DISTRIBUTION.

     The specimen we have described above, was obtained on the Western Prairies,
we believe on the east of the Mississippi river; the locality was not
particularly stated.  It was politely presented to us by Professor SPENCER F.
BAIRD, of Carlisle, Pennsylvania, a young Naturalist of eminent attainments.


                                GENERAL REMARKS.

     In every department of Natural History, a species is occasionally found
which forms the connecting link between two genera, rendering it doubtful under
which genus it should properly be arranged.  Under such circumstances, the
Naturalist is obliged to ascertain, by careful examination, the various
predominating characteristics, and finally, place it under the genus to which it
bears the closest affinity in all its details.  The Spermophili are intermediate
in character between the Squirrels and Marmots.  They have the lightness of form
of the former, and burrow in the ground like the latter.  By their cheek
pouches, of which the true Squirrels and Marmots are destitute, they are
distinguished from both.  The second inner toe on the forefoot of the
Spermophili is the longest, whilst in the Squirrels the third is longest.  But
in these closely-allied genera, there are species which approach those of
another genus.  Thus our Maryland Marmot, (A Monax,) has a rudimentary
cheek-pouch, in which a pea might be inserted, yet in every other particular it
is a true Arctomys.  The downy Squirrel, (Sciurus lanuginosus, see Journal
Acad. Nat. Science, Vol. 8th, part 1st, p. 67,) by its short ears, broad head,
and not very distichous tail, approaches the Spermophili, yet by its being
destitute of cheek-pouches, by its soft, downy fur, and its hooked, sharp claws,
of which the third, as in the Squirrels, is longest, it is more allied to
Sciurus.  On the other hand, the species now under consideration has the long
legs, slender form, and sharp, hooked claws of the Squirrel.  The two middle
toes of the fore-feet being of equal length, prove its affinity to both genera;
but in the general shape of its body, its cheek pouches, its short ears, and
smooth, rigid hair, it must be regarded as belonging to the genus Spermophilus.
We consider this species and the downy Squirrel as connecting links between
Sciurus and Spermophilus, as we regard Sciurus Hudsonius the connecting link
between Tamias and Sciurus.