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Show 1893.] MR. O. THOMAS ON MAMMALS FROM CENTRAL PERU. 337 Skull-basal length 17 ; greatest length 20*8 ; zygomatic 12; intertemporal breadth 5*6 ; palate, length 9*5, breadth outside vf 8*6, inside £^ 4-4 ; front of canine to back of jn2 6*5 ; ditto in lower jaw 6*9 ; horizontal length of Of 2*0, ^p 1*8, ^ 0*4. There is no necessity for any comparison of this species with its allies, as its dental formula distinguishes it at once from all except the A. perspicillatus group, of which the smallest member is of at least three or four times its bulk. A. glaucus is perhaps Tschudi's " Phyllostoma pusillum, Natt."but has clearly nothing to do with Natterer's species, which was placed by Dobson in the genus Chiroderma, and later on transferred by myself to Vampyrops2. 11. SCIURUS VARIABILIS, Geoff. a. Ad. sk. c$ . Chanchamayo. 12. SCIURUS CHRYSURUS, Buch. a. Ad. sk. J . La Gloria, Chanchamayo. 13. BHITHRODON PICTUS, Thos. a. Ad. sk. San Bias, Cordilleras, 18000 feet. 30/4/90. 14. ICHTHYOMYS STOLZMANNI, g. & sp. nn. (Plate XXVIII. and Plate XXIX. figs. 1-6.) ICHTHYOMYS, g. n. Form modified for an aquatic piscivorous life. Head markedly depressed, so as to give its side view a resemblance to that of a snake. Eyes and ears small. Whiskers long, stout, and prominent. Fur short and close. Hind feet (Plate XXIX. fig. 5) very broad; toes partially webbed, broadly and closely ciliated on each side; their soles, naked, with five broad low pads. Tail long, cylindrical, but increased in height vertically by having its under surface clothed with short elongated bristles. Caecum (fig. 6) much reduced in volume, very short, and only of the same diameter as the rectum. Small intestine of medium length ; colon and rectum proportionally short. Skull (figs. 1-4) curiously like that of Hyclromys, its dorsal outline concave over the orbits, flattened and depressed throughout. Supraorbital edges smoothly rounded, without any trace of ridges ; supraorbital foramina proportionally large, not within the orbit, but upon the top of the interorbital space. Infraorbital foramen exactly as in Hyclromys, as broad below as above; anterior zygoma-root very short horizontally, its anterior edge vertical, not projecting forwards. Zygomata extraordinarily weak, not properly ossified at the junction of the malar with the maxillary process. Palatine foramina of medium length. Teeth. Incisors with their front surfaces so turned in towards 1 Faun. Peruana, p. 63 (1844). 2 Ann. Mag. N. H. (6) iv. p. 170 (1889). |
