79 Annulated Marmot Squirrel
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.