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Show 1895.] NEW MOLLUSCS FEOM BOENEO. 247 form of the teeth. The lingual ribbon was extracted in a very perfect state, showing one hundred rows of teeth arranged thus 90-16-1-16-90 106-1-106. Generative Organs (figs. 32-35).-The vagina is larger than M. pollonerai, as is also the sessile receptaculum seminis, which is somewhat pyriform in shape. The penis opens into the vestibule as a comparatively narrow tube, but as it approaches the vas deferens it dilates into a large sac-like head, from which the flagellum arises; the latter organ is looped back upon itself and of the same diameter throughout, terminating blindly. In one specimen it was somewhat produced, as shown in figure 34. The vas deferens leaves the head of the penis as a wide tube, becoming narrower in the middle and dilating again previous to entering into the prostate. The common duct is similar to that in M. pollonerai, only not so richly convoluted; it differs also in being much straighter and not coiled upon itself as in M. pollonerai. The albumen-gland is small and ovoid. The hermaphrodite gland is small and triangular in shape, with a thin convoluted duct. 2. Affinities. The nearest species as regards internal anatomy to either of these two species of Microparmarion is Parmarion pupillaris, Humb., from Java, notwithstanding the fact that the shell is very rudimentary. It is figured by von Martens (5. pi. xii. fig. 3), who localizes Parmarion to this part of the world. The generative organs are figured by Semper (6), whose figure w e have reproduced for purposes of comparison. The form of the penis and receptaculum seminis and amatorial organ are very different from those in either of the species here described. The dart is cut off like a pen near the point (fig. 37). In the jaw and lingual ribbon there is a complete analogy. A comparison, however, of all the characters with those of Girasia of India and Burma shows that these Malayan forms differ sufficiently to constitute them a distinct race; and if w e could only obtain more material, in which other characters, such as the spermatophore, might be examined, a still greater divergence would, we think, be found associated with the small sessile receptaculum seminis. Simroth (7), in his latest paper on these slug-like land-molluscs, very rightly divides the genus into two, viz., Parmarion and a new genus Microparmarion, distinguishing this latter by the sessile receptaculum seminis and solid sagitta amatoria. It will be seen that among the Javan forms figured by him on plates vii. and viii., Microparmarion strubelli agrees in some respects with M. simrothi, particularly in the calc-sac of the male organ and in the hard calcareous dart rising from the funnel-shaped base, aud externally by the black lines on the dorsum and region of the head. In |