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Show 182 MR. W. A. FORBES ON THE KOALA. [Jan. 18, up towards the angle of the mouth) it is nearly so, a patch of black hairs being developed just behind the mouth on the lower and outer surface of this bare space. The marsupial pouch in this young specimen is very imperfectly developed. It appears as a small, oval, nearly naked space, measuring about 0-8 inch both across and antero-posteriorly, with a well-marked-bounding- fold of integument on each side ; inside which is a smaller, secondary one. The hairs of the surrounding parts more or less radiate from this nude space, which lies between the epipubes (or so-called "marsupial bones"). The skin covering it is pinkish. The teats are two1 in number, 15 millims. apart, and are situated at the posterior and inner angles of the bounding-folds; they are covered by fur. The lips of the pouch, it may be noted, look as much downwards as forwards. In an adult 2 Koala, 20| inches long, preserved in spirit, the pouch is much better developed-its antero-posterior extent being about 1-85 inch, whilst the breadth of the aperture is 1*4 inch. It admits (my) three median fingers, and extends widely outwards into the groins, as far as the skin-fold between the knee and trunk. The teats, two in number, are situated behind, on a level with the posterior margin of the pouch's mouth. The skin lining the pouch, except just around the ventral opening of the pouch, is smooth throughout. The mucous membrane of the cheeks is smooth throughout; the skin is attached to the gum opposite the first palatal ridge, and again opposite the posterior border of the first premolar. Between these two attachments there is formed a sort of cheek-pouch, defined by a distinct sphincter, and capable of receiving the end of the little finger. This pouch extends upwards on the side of the skull, occupying the somewhat oval space that exists, in the macerated skull, in front of the zygoma; it is lined by smooth, white, mucous membrane 2. The palate presents 9 irregular raised ridges, best marked anteriorly. There is no uvula, and the narrow fauces are smooth. The tongue quite fills up the space between the gums. It is parallel-sided and elongated, but rounded off and thinner in front. It has a single, small, circumvallate papilla behind ; the fungiform papillae are distributed chiefly along the sides of the upper surface. The salivary glands are well developed. The sublingual (which is' not mentioned by Martin in his description) is a long, narrow, and thin gland, somewhat foliaceous at the extremity, and about 2*7 inches in extent, lying deeply along the inner margin of the lower jaw. The long duct of the submaxillary gland pierces it. I could find no subzygomatic gland, as described by him {I. c. p. 112). On opening the abdominal cavity the stomach is visible in the 1 Prof. Owen (Anat. Vert. iii. p. 769) describes Phascolarctos as having four [" two on each side"] mammary glands. 2 These pouches are also, I find, described by Owen (Anat. Vert. iii. p. 385). They also exist, though less well defined by a sphincter, in the Wombat; but I cannot find them in the other Phalangers I have examined. |