OCR Text |
Show ~38 EXPLORATION OF 1'BE CA:RONS OF THE COLORADO. feet and tail are mostly whitish (as is always liable to be the case in Geomys). rrhere is some whitishness about the lower jaw, and a small white abdominal and anal patch; these last being of the irregular indeterminate character often seen in and out of this genus. This specimen corresponds exactly with Brunts's diagnosis of his var. /3. of mexicanus-" castaneus, infra canescens, maculis au1·icularibus duabus nigm-fuscis." The same author's var. y. suggests hispidus; but it is as well not to strain a point here; for injudicious scrutiny of some of the printed matter extant upon the suhject of mexicanus might raise synonymatic difficulty with hupidus. Owing to insufficiency of material, I am not prepared to pursue the subjec. t of the characters of mexicanus into the details of variation in size and color; but I have no doubt that it corresponds with G. bursa'rius in these respects. The specimen shows three pairs of mammre-two of which are inguinal and cl.ose togetl~cr along the inside of the thigh, the third being pectoral, a1. a constderable d1stance ; I can find none between. .. This an~~al i.s supposed to be the Tucan of Hernandez, with much probabihty; and, tf so, 1t was the first of the genus to appear in print. It does not appear, however, to have received a scientific designation, or to have properly entered upon record until many years after ''Mus bursarius" had become known, when, in 1827, it was called Ascomys mexicanus by Lichtenstein. I have met with no specific synonyms, though it has been referred to various ~enera.. A.s the Tuza or Tu<;a of the Mexicans, it is treated at some length m the med1ted MSS. of Dr. Berlanrlier who after a good desc · t' 1 · ' ' np wn, says t 1.at 1t was supposed by Mocinno and Scsse (ined.) to be the Mus citiltus of .L mnreus, a. nd .t hat it is the Taupe mexicaine of which Cl av·t gero speak s. , ' I t Is destructtve m the fields by riddlincr the ground 't b: · . . o · ... 1 nngs up earth 1n Its pouches, and empties them with its fore feet;" and he adds that it inhabits the cold and temperate regions of New Spain and that h h T · " ' • e never saw t e uz.a m pl~ces where there were squirrels. It is not to be inferred that its habits are m any wise different from those of G . bu rsan.u s. COUES ON GEOMYS AND THOMOMYS-G. IIISPIDUS. 239 GEOMYS HI SPIDUS, Lee. Snccophortlo3 quaohil, GRAY, P. Z. 8. xi, 1843,70, ex Coban, Vera Pa:t, dCBcr. nullai- GEnn., Cat. Bones Br. Mus. 1862, 223. Geomys hiBpidus, LEo., Proc. Acad. Nat. Sci. P biln. 1852, 1!i8.-DAIRD, M. N. A. 1857, 386, pl. 22, f. 4 a-d. Pseudostoma (Geomys) hispidum, Au D. &. B,tcn., Q. N. A. iii, 1854, 306. DIAGNOSis.-Superior inciso r~ with a single strong deep furrow, lying wholly in the inner half of the tooth. Tail and hind feet nal<ed, or ~early so; fore feet sparsely hirsute. F ore feet, .including claws, decidedly shorter than the hind feet. Pouches moderate, scarcely or not reaching beyond the head. P elage stiff, hispid, and almost lusterless. Color uniform dull chocolatebrown, merely paler, grayer, or smol\y brown below. Of large size ; upward of a foot long; tail short, about 3 inches; sole, l i , &c. HABITAT.-Mexico and Central America. Description (from various dried specimens).-The animal indicated in the foregoing paragraph, and about to be described in further detail, agrees perfectly with the accounts given by LeConte and Bai rd from the same specimen collected some years ago by Mr. Charles Pease, somewhere between Vera Cruz and Mexico City. The type remained unique until recent ly, when several well-prepared skins reached the Smithsonian. T hese are from Xalapa, Mexico (De Oca), and Necostla, Mexico (S umichrast) ; Costa Rica (Z eledon and Carmiot) ; and Guatemala City (Van Patten). Most of these specimens are labeled " mexicanus," as might have been expected under the circumstances. They agree perfectly with each other, as well as with the abovequoted descript ions, and are unquestionably distinct from the t rue mexicanus. In the original not ices, the character of the upper incisors was not fully indicated, owing to defect of the specimens. My specimens show that these teeth are unisulcate, as in mexicanus, but that the position of the groove is sufficiently different to constitute by itself a perfect specific character. In mexicanus, .as has been already said, a single profound groove bisects the tooth; in hispidus, there is a similar single groove, but it lies on the inner half of the tooth. In some specimens, indeed, where the groove is widest, it may encroach slightly upon the median line; but it usually lies altogether to one side, the outer plane surface of the tooth being alone as wide as the groove plus the inner plane surface. T his character is unique among the species |