86 ^Ir. 0. Thomas on a new IX. — A new Aquatic Genus of IMurida^ discovered hj Consul L. Soderstr'um in Ecuador. By Oldfield ThOMAS. Among a further consignment of small mammals which the British l\Iuseum owes to the generosity of Consul L. Soder-stiiim, of Quito, there occurs a most interesting new form, ilie type of tiie following description : — Anotomys, gen. nov. External characters as in Ichthyomys^ but ear-con.ch quite rudimentary and the ear-opening itself a mere minute slit. Fur exceedingly rich and velvety, almost wholly composed of wool-hairs. Feet strongly fimbriated. Skull with the brain-case smooth, round, and inflated, like that of a young non-aquatic Murine, not flattened as in Ichthyomys. Muzzle set on in a peculiar manner, appearing to be bent upwards owing to the strong angle at which its upper profile meets the marked rise of the frontal, and to this jirotile continuing perfectly straight anteriorly without any descent towards the tip of the nasals. Nasal opening not slantmg backwards in lateral view, but practically vertical, the tip of the nasals projecting in front of the main part of the premaxillre, but in turn just surpassed by the unusually projecting gnathic point between the incisors ; in front view the opening is high and narrow, approaching "guttate" of Ridgway, while in Ichthyomys it is nearly " deltoid " (the point, of course, downwards in each case). Anteorbital Ibramina essentially as in Ichthyomys, or even more open ; the anterior zygoma-root, both above and below, very slender and delicate. Malars absent on both sides in the type, possibly never ossified. Palatal foramina much broader behind than in front, instead of being approximately parallel-sided. Po-sterior palate less extended behind the molars. Incisors narrower and less specialized than in Ichthyomys, the lower ones particularly narrow, with long slender points; a marked laterally projecting incisive capsule over the root of each upper incisor, in front of the anteorbital foramen. Molars apparently as in Ichthyomys^ but much worn in the only specimen. Type, A. leander. This genus is evidently closely allied to Ichthyomys^ but is less specialized for an aquatic piscivorous life in some direc-tions (shape of brain-case, structure of incisors), and more so
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