Article III.-DESCRIPTION OF A NEW SPECIES OF PEROGNATHUS FROM SOUTHEASTERN TEXAS.

By J. A. ALLEN.

During the last few months the Museum has received a large number of mammals collected in the vicinity of Brownsville, Texas, among which are numerous specimens of a small species of Perognathus, apparently hitherto undescribed. It is allied to P. flavus, but evidently quite distinct from it, and may be described as follows:

Perognathus merriami, sp. nov.

Externally of the size and general proportions of P. flavus, but brighter and more yellowish in coloration, the sides being strongly yellowish or golden instead of pale cinnamon.

Measurements (average of three adult specimens): Total length, 115 mm.; head and body, 60; tail, 55; hind foot, 17; ear, 4.

Skull, greatest length, 23 mm.; basilar length (occipital condyle to incisors), 16.5; greatest mastoid breadth, 12.7; least intermastoid breadth, 4; least interorbital breadth, 5.1; length of nasals, 11.5; greatest zygomatic breadth, 11.5; length of upper tooth row, 3.3; breadth of palate at posterior border, 2.8; breadth of palate at anterior border, 2.3; from hinder edge of palate to inner base of incisors, 6.6; length of lower jaw, 12.7; height at coronoid process, 4.6. Type, No. 11, ad., Brownsville, Texas, Aug. 10, 1891; F. B. Armstrong.

4145

Compared with the El Paso specimens of P. flavus (kindly loaned me for examination by Dr. C. H. Merriam), taken Dec. 12-14, 1889, P. merriami differs markedly in coloration in its generally brighter yellowish color, particularly along the sides. A comparison of the skulls reveals very marked differences, not only as regards the general form but in the relative size and form of special parts, as shown in the series of figures in Plate III. In P. merriami the skull is much larger and disproportionately broader in proportion to the length. The mastoids are shorter and less developed, leaving a much broader intermastoid area, with the interparietal much broader than long, instead of nearly square as in P. flavus. The figures represent-for purposes of

comparison, and also to show individual variation-three skulls of P. flavus, and six skulls of P. merriami, as seen from above, drawn twice the natural size.

In addition to the three El Paso specimens of P. flavus mentioned above, I have three from North Beaver River, Indian Territory (near the northern boundary of Texas), and one from Presidio County, Texas, that seem also referable to P. flavus.

P. merriami is based on a series of 17 specimens from Brownsville, Texas, belonging to this Museum, while a considerable number of additional specimens have passed through my hands. They were taken at various dates covering a period of over four months (July to October, inclusive), and include young and adults. The July and August specimens are a little grayer and less fulvous than those taken late in September and October. In all the tail is naked, and the pelage coarser than in P. flavus. The species is named in honor of Dr. C. Hart Merriam, Chief of the Division of Economic Ornithology and Mammalogy, U. S. Department of Agriculture.

64

ad. No.

9, Sept. 13, 1891.

9 ad. No.

1, Oct. 9, 1891.

7. Perognathus flavus, No. 2357, Coll. Dr. Merriam, El Paso, Texas.

Article IV.-ON A SMALL COLLECTION OF MAMMALS FROM THE GALAPAGOS ISLANDS, COL

LECTED BY DR. G. BAUR.

By J. A. ALLEN.

Dr. G. Baur, of Clark University, Worcester, Mass., has kindly placed in my hands for identification and description, the small collection of mammals recently obtained by him on the Salisbury Expedition to the Galapagos Islands. The collection numbers 12 specimens, representing 4 species. Two prove to be introduced species of Mus, while one is a Bat of the genus Atalapha, and the other a species of Oryzomys, allied to O. galapagoensis (Waterh.).

Atalapha brachyotis, sp. nov.

Apparently similar to Atalapha varia (Poeppig) from Chili, but rather smaller, with disproportionately smaller ears, and shorter thumb.

General color above reddish chestnut, the hairs plumbeous at base, broadly ringed subapically with yellowish rufous and tipped with chestnut, much darker on the lower back and tail; below blackish with the tips of the hairs ashy. Ears small, rounded, blackish, as also the lips. Wing and interfemoral membranes black, as are also the fingers. Posterior half of the interfemoral membrane very thinly haired.

Measurements.-Head and body, 47 mm.; tail, 44.5; ear, 7.6; tragus, 4.3; forearm, 39; thumb, 6.4; second finger (matacarpal), 42; third finger (metacarpal, 43.2, 1st phal., 16, 2d phal., 16.7, 3d phal., 3=) 79; fourth finger, 63; fifth finger, 53; tibia, 20; foot, 8.4.

Based on a single specimen in alcohol, collected on Chatham Island, June 23, 1891.

As nearly as can be judged, this insular form closely resembles A. varia in coloration, size and proportions, except that it has much smaller ears. The hariness of the interfemoral membrane is apparently similar in both, in A. brachyotis there being only a few short hairs beyond the basal half.

Compared with A. noveboracensis of North America, aside from the striking color differences, A. brachyotis is a much slenderer form; while the linear measurements are about the same, the

body is much smaller, and the wing bones much more slender. There is also a marked difference in the dentition, which is very much slighter, notably shown in the size of the canines, which in A. brachyotis are only about half as large as in A. noveboracensis. Dr. Baur writes me: "On Chatham Island, at an elevation of about 1700 feet, where the hacienda is placed, we observed bats nearly every evening, but were for a long time unable to kill a specimen; the one I send, the only one collected, was shot by Mr. Adams.

"Bats have been observed on Indefatiguable Island by Dr. Habel, and I observed one on South Albemarle."

Mus decumanus Pall.

Mus jacobia WATERH, Zool. Voy. Beagle, I, pt. ii, 1840, p. 34.

I refer to this species a mummified specimen, "found dead on Albemarle Island, opposite Crowley Island, Aug. 9, 1891." It is an adult, and measures as follows: Head and body, 190 mm. ; tail, 203; hind foot, 34. Above the general color is yellowish chestnut, profusely mixed with longer wholly black hairs, passing into yellowish brown on the sides; below buffy white at the surface, the hairs from near the tips to the base pale sulphery white. This seems to be the form collected by Darwin (op. cit.) on James Island, where he found it very common, but he does not appear to have actually met with it at any of the other islands.

Mus rattus Linn.

Represented by one specimen in alcohol, about two-thirds. grown, apparently not distinguishable from an ordinary black rat of corresponding age. It was taken on South Albemarle, July 29, 1891.

I also refer provisionally to this species an imperfect skeleton found on Duncan Island. This specimen consists of the skull and anterior half of the spinal column, of a full-grown but not aged individual, agreeing in size with Mus rattus.

Oryzomys bauri, sp. nov.

Evidently allied to Oryzomys galapagoensis (Waterh.), but differing from it in proportions and coloration.

Pelage full and long. General color above dusky grayish brown, faintly varied with pale yellowish brown; below the pelage is white at the surface, passing into plumbeous. Muzzle lighter and more grayish, tinged strongly with yellowish brown on the sides of the muzzle and faintly so on the chin. Ears large, obtusely rounded, almost naked within, well haired externally on the anterior third, and sparsely haired over the rest of the outer surface. Feet above thinly haired, white faintly tinged with yellowish; soles naked, 6-tuberculate; posteriorly smooth and pale horn color, anteriorly granulated and yellowish, slightly varied with gray. Tail indistinctly bicolor, nearly naked, the annulations showing distinctly through the very short hairs; above dusky brown, below ashy brown.

Measurements.-Male Adult: Total length, 280 mm. ; head and body, 132; tail, 147; hind foot, 32.5; fore foot, 18; ear, 18. Female Adult: Total length, 269; head and body, 124; tail, 145; hind foot, 31; fore foot, 16.5; ear, 17.3. Young Male: Total length, 248; head and body, 108; tail, 138; hind foot, 16.5; fore foot, 14.5; ear, 16.5.

Skull, ad. Total length, 37.4; basal length (condyles to incisors), 27.5; greatest zygomatic breadth, 18.3; least interobital breadth, 5.6; length of nasals, 13.5; from posterior border of palate to incisors, 14.7; length of lower jaw (tip of incisors to condyle), 22.8; height at condyle, 9.9.

Based on 5 specimens in alcohol, namely, I male adult, I male two-thirds grown, I male half grown, I female adult, and I female about half grown, taken on Barrington Island, July 9 and 10, 1891. There are also three inverted skins in antiseptic solution, taken at the same place and time. The adult male may be considered as the type.

This species is apparently nearly allied to 0. galapagoensis, described by Waterhouse from specimens collected by Darwin on Chatham Island, about thirty miles east of Barrington Island. While of about the same size as O. galapagoensis, it has larger ears, and the tail is half an inch or more longer than the head and body instead of being an inch or more shorter, as in O. galapagoensis. In coloration it is evidently much less varied with yellow, as in O. galapagoensis, the prevailing color on the sides of the body is described as yellow. In O. bauri the coloration is about as in Sigmodon hispidus-the prevailing color being dusky gray, with only the slightest mixture of pale yellowish brown. The young are slightly darker than the adults; the female has a slight mixture of pale yellowish-tipped hairs.

O. bauri, and doubtless also O. galapagoensis, is a true Oryzomys, as regards the skull and dentition; it has, however, a much [May, 1892.]

4