OCR Text |
Show 1868.] MR. P. L. SCLATER ON A NEW URSUS. 71 Again, the ulceration apparently took a longer period to attain the chronic stage extant than the few weeks' residence of the Walrus in the Gardens would account for. Furthermore, the nature of the food given at the Gardens, and the care and regularity with which it was examined, make it unlikely that such swarms of Entozoa were derived from it and developed in so short a period. Whether the Entozoa had been derived from the food given on board ship, or in what manner they had originally reached the stomach of the Walrus, are questions which I am quite unprepared to answer; and speculation leaves the matter quite as undecided. Dr. Baird has furnished the subjoined description of this Ascaris, which proves to belong to a new species. ASCARIS BICOLOR, Baird. Head naked ; labia distinct, prominent, rounded, and of moderate size. Both anterior and posterior portions destitute of alee or wings. Body of worm cylindrical, attenuated anteriorly, of a brownish colour, except at the anterior extremity, which is white; the posterior extremity is sometimes red. The surface of the body is beautifully and minutely but distinctly striated across ; as seen under the microscope (with a power of two-thirds of an inch), the striee on each side terminate in such a manner that the edges of the body appear as if serrated. Caudal extremity thicker than anterior, obtuse, and generally convoluted. A great many specimens were found in the stomach; but apparently all were females. The Ascaris simplex of Rudolphi, found in the stomach of the Porpoise (Phoceena communis), very nearly approaches this species in general appearance and size, but differs from it in several respects. The Ascaris bicolor is less attenuated at the anterior extremity than the A. simplex, and is destitute of alee or wings equally at the posterior and at the anterior extremity. The striations on the surface of the body are much finer, and the labia or valves at the mouth are more distinct and larger. Length from 2\ to 3 inches; breadth from 2 to 2\ millimetres. Hab. Stomach of a young male Walrus (Mus. Brit.). February 13, 1868. John Gould, Esq., F.R.S., V.P., in the Chair. Mr. P. L. Sclater called attention to a Bear recently added to the Society's Menagerie, which appeared to be distinct from every recognized species. In general appearance it somewhat resembled the American Black Bear (Ursus americanus), but differed in its finer fur, larger and less densely clothed ears, pale brown muzzle, and white crescent-shaped mark on the chest, which was connected with |