On new Mammals from the Yeotropical Region.

THE ANNALS AND MAGAZINE OF NATURAL HISTORY, INCLUDING ZOOLOGY, BOTANY, AND GEOLOGY. ( BEIKG A CON'J'DlUATION OP THE 'AN"N"ALS' CO�IRJKED W[Tll LOUDON AND CIIARLESWORTll•S I MAGAZINE OF NATURAL HISTORY,') CONDUCTED BY AU!EltT C. L. G. GUNTHER, M.A., M.D., Ph.D., F.R.S. WII,LIAM CARRUTHERS, F.R.S., F.L.S., F.G.S., ANO WILLIAM FRANCIS, Ph.D., F.T,.S. VOL. XVIII.-SIX'fII SBHIES. LONDON: PRINTED AND PUilLISIIED IlY TAYLOR AND FR.\NCIS. f:OLD BY SIMPKIN, MARSIIALL, JIA�ULTON, KENT, A:\"D CO., LD.; WHITTAJ{lUt • .\ND CO.: Il.\lLLd:nE, PAIUS: MACLACHLAN .AND STEWART, EDl�BURGII: UODGKS, FIOGIS, AND CO., DOOLIN: AND ASll.ETI, BERLIN. 1896. THE AN:N ALS AND )fAGAZINE OF NATURAL HISTORY. [SIXTH SERIES.) .No. 106. OCTOBER 1896. Ann, & Jlag, N. Hi"st. Ser. 6. Vol. xviii. 20 On new .Mammals from the ,Yeotropical Region. 301 XLVI.-On new small Mammals.from tlte Neotropical Region. By OLDFIELD THOMAS. DURING the past six months several collections of small mammals from different parts of Uentral and Sonth America have been received at the British Museum, and among these there are a certain number of new species, which may be conveniently all described iu one paper. GLYPHONYCTERIS *, gen. nov. (Fam. Pl,y/lostomatidw; group Varnpyri.) Nose-leaf narrow, bound down to the muzzle in front. Chin-warts apparently only two, one on each side of a central • y"/..vcjmv, to chisel. 302 J\lr. O. Thomas on new ]fammals groove. Ears separate, not connected across the head. Tail short, perforating the interfemoral membrane and appearing on its upper surface. 1Ving-membrane from the side of the ankle. Skull thin and papery. Profile-line from top of muzzle to crown nearly straight, not markedly concave. Anteorbital region broad, with a distinct inflation just above the anterior corner of each orbit, the breadth of the muzzle over the ante orbital foramina much greater than the postorbital breadth. Dentition.-!.�' C. t, P. �, J\I. jx2=3-!. Upper middle incisors large, vertical, chisel-shaped, their cutting-blades broad, very thin antero-posteriorly. Outer incisors minute. Canines short, sharply pointed, their antero postcrior basal about cq ual to their vertical diameter. Pre molars subequal, oval or rounded in section. Lower incisors distinctly tricuspid, subequal. Canines low, scarcely ex ceeding the other teeth in height. Premolars subequal, the median one fully as large as the other two. This genus is evidently most nearly allied to Micronycteris (Schizostoma of Dobson's Catalogue), but differs by its uncon nected cars, broader nrnzzle, inflated anteorbital region, straight frontal profile, and peculiar chisel-shaped incisors. No other <lescribcd genus shows its short tail, dental formula, and well .developed middle lower premolar. Glyplwnycteris sylvestris, sp. 11. Externally very similar to Hemiderma brevicauda, though rnthcr smaller*. Ears short, their tip forming an almost square angle, the outer and inner edges distally being approximately at right angles to each other; lower part of outer edge ending in a low rounded lobule. Fnr soft and £ue, not extending on to the wings or limbs, except that the pollical metacarpals and the backs of the feet arc thinly tufted. Colour above mixed smoky grey, the hairs <lark smoky basally and terminally, white for their middle third; below they are smoky basally and dull whitish terminally. Interfemoral memurnne broad, extending in the middle liue to the level of the distal third of the tibilll. Skull and teeth as described above. • This resemblance is so great that almost the only character which .affords a ready means of distinguishing the two is the short and delicate thumb of Glyplwnycteris as opposed to the long heavily clawed one of Hemiderrna, In colour the two are almost identical. from the Neotropical Region. Dimensions of the type (an adult male skin): Forearm 40 millim. (=1·5G inch). 303 Head and body (measured by collector in flesh) 50 millim.; ear (dried) 17; thumb, with claw, 9·2; middle finger-meta carpus 3(:i, first phalanx 13·5, second phalanx 20, third phalanx 10·5; tibia 15; hind foot, with claws, lO·G; calcar 7·2. l::ikull: greatest length 19·G; basal length 16; greatest breadth 9·6 ; breadth of muzzle at inflations, just over ante orbital foramina, 5·7; interorbital breadth 4·6; front of upper canine to back of m, 3 8. /fob. lmravalles, Costa Rica. Coll. C. F. Underwood, Nov. 8, 1895. Rhipidomys venezuelw, sp. n. Closely allied to Rh. macrurus, Gerv., with which it shares the general rich rnfous colour, long tail, and sharply defined pure white belly. Ears large, much larger and, especially, broader than in Rf,. macrurus. General colour above rather orange-rufous in the type (an old male), but in a younger female clearer rufous, similar to some specimens of Rh. Sumi chrasti. Hands and feet, as usual, with the metapodials brown mesially, the remainder and the digits white. Tail long, uniformly dark brown above and bel011·, hairy and tufted, but less so titan in most of the larger species of the group. Skull with fairly long nasals; a rather narrow interorbital region, whose edges are sharply ridged. Interparietal large, its anterior edge very concave forwards. Anterior palatine foramina extending backwards to the level of the front edge of m.1. Dimensions of the type (an adult male, measured in the flesh by collector) :- Head and body 155 millim.; tail IGO; ear 20. In the dried state the hind feet arc 28 millim. long and the ear haa shrunk to 19 millim. Skull: basal length 31·2; basilar length from henselion 29; greatest breadth 19·5; nasals 12 X 4; interorbital breadth 5·2, interparietal 5·1 x 9·2; palate length from henselion 15·1; diastema 10; anterior palatine foramina 7·6 x 3; length of upper molar series 5· l. llab. Merida, Venezuela, alt. 1630 metres. Coll. S. Briceno, .illarch 5, 189G. Besides the differences in the size of the ears and the hairiness of the tail this species differs from Rh. macrurus by 304 111 r. 0. Thomas on new lifammals its <lecidedly narrower interorbital region and slenderer muzzle, the sarne cranial characters also separating it from Rh. lati manus. Rhipidomys microtis, sp. n. A rather small llln'pidomys, with a scarcely pencilled tail and very small ears. Fur close and soft. General colour fulvous, duller and less rufous than in the majority of this group; perhaps nearest to Ridgway's "clay-colour"; in the centre of the back finely lined with black, clearc\' on the sides. Under surface white, the hairs white to the roots; line of demarcation on sides of belly less well defined than usual. Whiskers long and numerous. Ears small and narrow, thinly haired, pale brown. l\letapodials brownish, digits dull white, but the difference little marked. Tail long, very finely scaled, uni formly brown throughout; scarcely more bushy than in non Rhipidomyine Vesper-rats. Skull of only specimen unfortunately much broken. l\fuzzle short and narrow, supraorbital ridges sharp. Zygo matic plate not projected forwards. Anterior palatal foramina long, reaching backwards to the level of the first lamina of m. 1 lllolars as usual in the group. Dimensions of the type (an adult male iu skin):- Head and body 109 millim.; tail 136; hind foot 25; ear 12 x 9. Skull: basilar length from henselion (c.) 22; nasals 9·6x 3·4; interorbital breadth 4·8 ; palate length from lienselion 11 ·5; diastema 7·3; anterior palatine foramina 6 x 2·6; length of upper molar series 4·7. Hab. Salina de! Vatan, ·western Cundinamarca, Co lombia. Type killed Nov. 16, 1895. Rhipidomys fulviventer, sp. n. About the size of Rlt. microtis. Fur very thick and soft. General colour above fulvous, thickly lined with black. Underside clearer fulvous or even buff, the line of demarca tion scarcely marked; hairs of belly slaty grey basally, buffy terminally. Chin and chest whiter. l\Iammre 1-2=6. Ears rnther small, uniformly brown. llletapodials with the usual piebald patches strongly marked; digits pure white. Tail long, uniformly brown, not very thickly haired basally, but with a long a11d well-defined pencil terminally. Skull with a large rouuded brain-case and slender narrow from the Neot,·opical Re,qion. 305 face. Interorbital region flat, its edges square, not heavily ridged. Palatal foramina rather narrow for the group, ex tenJing backward to the level of the front of �. Hullre rather, though not measurably, larger than in the allied species of the group. Dimensions of the type (an adult female in skin):- Head and body 113 millim.; tail 125, with terminal tuft 141; hind foot (moistenecl) 24; ear (dry) 14. Skull: basal length 25·7; basilar length from henselion 23·8; greatest breadth 16·G; nasals 10·5 x 3·7 ; interorhital breadth 4·3, interparietal 4·1 x 10·6; palate length from hensclion 12·8; diastema 8; palatine foramina G·2 x 2·2; length of upper molar series 4·7. Lower jaw: condyle to incisor-tip 18·8. Hub. Agua Dulce, \Y. Cunclinamnrca, Colombia. Type collected Sept. 19, 1893. Tbis pretty Vesper-rat differs from all other mcmbe,·s of Rl,ipidomys by its slate-mixed fulvous belly, this part being in the other species perfectly pnre white. A very yo,rng specimen from Fauabist,i corresponds in all respects with the old one. 0ryzomys niveipes, sp. n. General appearance remarkably like 0. laniger, Thos., although it is slightly larger. Fur very long, soft, and fluffy. General colour dull olivc-fulvous, darker mesially above, clearer and paler along the sides and bclolV; line of demarcation on sides indistinct. Hairs everywhere above and below slate-coloured basally. Ears large, well-haired, black. Hands and feet silvery white above, without darker meta tarsals. Tail long, thinly haired, brown above, paler below. Skull very different from that of 0. l,am"ger. Face long and slender, with a narrow muzzle and long, narrow, parallel sided interorbital region, whose edges are rounded and not ridged. Brain-case smoothly rounded, not broad in propor tion to its length. Zygomatic plate little projected forward. Palatal foramina reaching just past the anterior end of "=-2. Dimensions of the type (an adult male in skin):- Head and body 113 millim.; tail 140; hind foot 26; ear 18. Skull: basal length 26·8; basilar length from henselion 2,5 ; greatest breadth 16; nasals 12·4 x 3·8; intcrorbital breadth 4, intcrparietal 3·5 x 10·5; palate length from hen selion 13·2; diastema 8·7; palatal foramina 7 x 2·4; length of upper molar series 5. Lower jaw: condylc to incisor tip 19·5. 306 i'ifr. 0. Thomas on new JJlammals Hab. La Oya de! Barro, \V. Cundinamarca, Colombia. Type collected Sept. 2, 1895. The resemblance of thiR species externally to 0. laniger is so great that practically the only means of distinguishing the two lies in the brownish feet or, rather, metatarsals o{ 0. laniger as compared with the silvery-white ones of the new form. The sknlls, however, are wholly different from one another both in size and proportions. 0ryzom,11s (?) lugens, sp. n. Very similar in all respects to the peculiar 0. i"nccinus described recently from Peru"· .Fur soft, close, and velvety. General colour finely grizzled olive-brown, but little lighter below than above. Ears large, brown. Hands and feet slender, thinly haired, brnwn above, the hairs at the bases of the claws whitish. Tail about the length of the head and body, uniformly thinly haired, brown above, rather lighter below. Skull in shape almost su.;gesting that of an 0xymycterus or A codon. J\J uzzle long, cylindrical. Interorbital convex above and rounded laterally, without trace of ridges; indeed, a section through the nasal chamber between the orbits would present an almost circular outline. Brain-case narrow, smoothly rounded. Zygomata very slender, little expanded, their anterior root narrow, slanted, without projecting plate. Palatine foramina extending back to the level of the front of m. I Lower jaw very slender, matchiug that of 0. incanus. Molars rntlier Acodont in appearance, with comparatively higl1 crowns; m. 1 with its anterior lamina unicuspid, so as to present only five cusps in all. J\leasnrernents of the type (an adult female in skin): Head and body 114 millim.; tail 118; hiud foot 27; ear 17. Skull: basal length 26; basilar length from henselion 24; greatest breadth ]4·8; nasals 12·2 x 3·8; interorbital breadth 6; breadth of brain-case 12·8; anterior zygoma-root 2·1; length of palate from henselion 13·2; diastcma 8·3; palatine foramina 5·9 x 2·6; length of upper molai· series 4·8. Lower jaw: condyle to incisor-tip 19·7. Bab. La Loma de! Morro, near Merida, V eneznela, alt. 3000 metres. Coll. S. Briceno, J\Iay 18, 1896. "Eyes black, excessively small. J\Iakes its nest in trees." -S. Bri"ceno. *Aun. & Mng. li"at. Hist. (6) xiY. p. 3W (1�04). from the Xeotropical Region. 307 As in the cnse of" Oryzomys" incan>ts, it is impossible to assign a sntisfactory position to this species, which differs in nearly every respect from typical members of the g-enus; bnt without a far more extensive knowledge of South-American :Mnrines than is possessed at present, it would be unwise to add to the number of named gronps of what used to be called "Hesperomys." \Yithou.t doing this, however, I frankly confess myself incapable of finding a proper place for the present animal, and merely put it nominally under the heading of Or'yzomys as a temporary expedient. Its slender form and long tail separate it from Acodon, its nail-clad pollex and normal muzzle show that it is not an Oxymycte,-us, while its narrow brain-case and rounded interorbital region separate it from all the ordinary species of 0,·.11zomys. As a species 0. lll_gens seems really most closely allied to 0. incanus, from which it differs by its much narrower brain-case, more rounded interorbital region, and differently shaped zygomatic root. Externally it seems very similar, but as the type of one is in spirit and the olhe,· in skin, an accurate comparison of the quality and colour of the fur is not at present possible. Eligmodon * Jlforeni, sp. n. Size rather large as compared with the very small species composing the group. Fur long and soft, but not woolly. General colour above coarsely mixed fawn and brown, clearer fawn on the sides. Belly, as usual, pure white or yellowish white. {Immature specimens have the bases of the belly hairs slate.) Ears large, oval. Palate-ridges 3-5. Upper sides of bands and feet silvery white. Palms and soles as usual in tbe group, granulated, with a large more or less hairy and corrugated pad at the base of the finger., ancl toes; a smaller more defined pad at the bases of pollex and hallux, and another a little way behind the last-named. Tail longer than the head and body, slender, thinly hairy throughout, blackish above, white below and on the sides. Skull stoutly built, with a broad muzzle. lnterorbital region flat, its edges square, not beaded. Anterior palatal foramina reaching backward one third the length of "'__:_!, Posterior nares very narrow. Dimensions of the type (an adult male in spirit) :- Head and body 80 millim.; tail 91 ; hind foot 23; ear 17. • Caloniys, Waterh. (1837) nee Is. Geoff. (1830). E,ir1111odontia, F. Cuv. 1837. Jie.,peromys, Waterh. 183!!. 314 Messrs. J. C. lllelvill ancl J. II. Ponsonby on large, their internal basal projection small; a rounded lobe at the base of their outer e<lge. Fur close, soft, an<l velvety. General colour above a dark smoky or bistre-brown, a dull huffy tinge prcsrnt on the fore back and sides. Under sur face dirty whitish, the slaty. bases of the hairs showing through; line of demarcation on sides fairly well defined. Colonr of face, limbs, and tail as in M. incana. f:kull similar in its general proportions to that of JJf. in cana, but decidedly smaller. Supraorbital edges not beaded. Anterior palatine foramina cxten<ling backwards only to the eanines. Canines very short. l\liddle upper premolars longer horizontally than vertically, very narrow transversely. Dimensions of the type (an a<lult female in skin, appa rently somewhat contracted) :- Head and body 118 millim. ; tail 138; ear 19. Skull: lambda (back end of parietal suture) to nasal tip 29; greatest breadth (c.) 17; nasals 14 x 4; interorbital breadth 6; intertcrnporal brea<lth 6·1 ; palate length 18; palate breadth between outer corners of m. 3 9·6. Combined length of m. l-3 5·5. llab. Rio Abbaregas, lllerida, Venezuela, alt. 1630 metres. Coll. S. Briceno, April 6, 1896. The l\Jerida collection contains three species of the JJ1ar mosa group, of wl1icl1 the lnrgest is a typical Jl,f, mudna and the smallest is so like M. pusilla that, in spite of the con siderable extension of tl,e known range involved, I do not see auy reason for distinguishing it. The middle one, however, although it may be said to represent JJf. incana, cannot be actually assig11ed to that species, from which it differs by its decidedly smaller size and much darker colouring, notably that of the lower surface. No other described species is at all like it.