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Show 1882.] ANATOMY OF THE INDIAN DARTER. 209 male, lived in excellent health till December 21st last, when it died suddenly, its death apparently having been caused by some sudden shock produced by too rapid feeding, as a dozen small fishes, just swallowed, were found in its stomach. No disease whatever could be found. It is this specimen that forms the subject of tbe present communication. As regards its stomach, Plotus melanogaster closely approaches P. levaillanti, the proventriculus being in the form of two quite separate patches, and the pyloric lobe being provided with a similar hair-covered conical and retractile " plug." In P. anhinga, it will be remembered, the proventricular glands are collected together into a special diverticulum of the stomach, whilst the pyloric lobe, though hairy internally, has no such plug. In P. melanogaster the two gland-patches have the form of watch-pockets, which nearly, though not quite, unite with each other superiorly. They measure 1*1 inch transversely and '8 inch from above downwards, being thus a little larger than the similarly shaped and situated ones of P. levaillanti1. There is no trace of the elevated " U-shaped ridge " situated on the anterior wall of the stomach between the two patches, described and figured by Prof. Garrod in the last-named species. The gland-patches are covered, as is the rest of the interior of the stomach, by the usual yellow wrinkled " epithelium." This ceases abruptly above at the level of the upper margins of the glandular areas, where it meets the smooth and pink mucous membrane of the oesophagus. Along this line of junction, the epithelial coat is thicker and jagged, an appearance probably due to several thicknesses of this coat having been " moulted " (as we know happens in the American species) and not come clean away2. The second, or pyloric, stomach is quite as distinct in Plotus melanogaster as it is in the two other species of the genus dissected. Like these, too, its pyloric half is covered internally with the peculiar hairy mat already described in these birds : the cardiac part, on the other hand, is covered by a yellow " epithelium " continuous with that of the rest of the stomach. The hairy covering forms a complete ring, thickest and best developed inferiorly-on the surface corresponding to the "greater curvature" of the Mammalian stomach-and quite surrounding the equally hairy pyloric plug. This "plug " is not a free process : it is rather a well-defined ridge, nearly cylindrical in section, attached superiorly to the wall of the stomach, but ending freely below. It, particularly towards its termination, is thickly covered with hairs of a similar character to those in the rest of the hairy region. When fully retracted, it completely fills up the centre of the hairy ring already described, the communication of the cavities of the stomach and duodenum being reduced to a narrow aperture situated below the plug, and only capable of allowing the passage of a bristle. i In the proventricular glands being limited to distinct areas, which do not unite to form a zone, Plotus levaillanti and P. melanogaster resemble the genus Phalacrocorax. 2 Cf. Bartlett, P. Z. S. 1881, p. 247. P R O C ZOOL. Soc-1882, No. XIV. 14 |