OCR Text |
Show 1897.] NEW SLUGS FROM BORNEO. 779 Anatomy of the Generative Organs. The vagina is a thick-walled tube slightly constricted in its upper portion ; from the lower portion the receptacular duct arises, as a narrow, somewhat long tube, enlarging into a globose receptaculum seminis; in the example examined this was empty and presented the large leaf-like appearance shown in the figure (PL X L I V . fig. 3 r.s.). The penis is short aud constricted in its lower half, its upper portion being bead-like (Pl. XLIV. fig. 3p), a feature common to a large number of species, the vas deferens passes off from the inner side (left-hand side) of the penis. The retractor muscle has its attachment immediately above the commencement of the vas deferens. The common duct formed by the oviducal and prostatic canals is thrown into a series of closely wound folds. The albumen-gland is somewhat ovoid in form. The hermaphrodite gland is a small oval-shaped body, attached to the thin convoluted tube, the hermaphrodite duct. The dart-sac is a comparatively short, wide tube, folded upon itself at its upper portion; unfortunately no dart was present. Affinities. The nearest species, as regards the internal anatomy, to this species is the P. rnartensl, Simr., in which species (cf. Pl. XLIV. fig. 4, reproduced from Simroth's original figure1) we have the elongated form of the receptaculum seminis and a similar shaped penis. P. everetti differs however from P. rnartensl in the altogether different shaped dart-sac; in the latter species this organ is constricted in its middle, the upper half being bent upon itself. Externally the two species are quite unlike. PARMARION INTERMEDIUM, n. sp. Hab. Lombok (1500 ft.), Borneo (A. H. Everett). Shell oval in form, convex, membranaceous borders larger than in P. everetti, and covered by the mantle, amber-coloured; lines of growth well marked, apex obscure. Major diam. 18*5 millim.; minor diam. 12*5 millim. Animal (Pl. X L I V . figs. 5 & 6) very dark green, almost black, lighter beneath the mantle; sides of the body greenish brown; posterior region of the body very dark green, almost black, becoming lighter anteriorly. Mantle-lobes black. Bugae not very prominent, elongated in the posterior region. Foot-fringe nearly black, with fine yellow lineoles. Foot-sole divided into median and lateral planes, the former yellow in colour, the latter almost black. Caudal mucous pore a deep vertical slit, not extending to the foot-sole, the sides of the pore are white (Pl. XLIV. fig. 7). Length (in alcohol) 43 millim. Anatomy of the Generative Organs. The vestibule commences as a wide pouch-like cavity, from 1 Zool. Ergebnisse einer Eeise in Niederlandisch Ost-Indien, 1893, pl. viii. fig. 20. |