22 Mr. Goodsir on the Anatomy of the Limneus itivolutus. V. — Description of Limneus involutus^ Harvey^ MS. By W. Thompson, Vice-President of the Natural History So-ciety of Belfast ; — with an account of the Anatomy of the Animal. By John Goodsir, Esq. [With a Plate.] Limneus involutus^ 1 tt T»m Amphipeplea involuta,j ^' Spec. Char. Spire sunk within the outer whorl ; aperture very large, extending to the apex. The finest specimen I have examined is 5| lines in length, and 3^ in breadth ; volutions four, the largest enveloping the other three, of which none are visible in the profile of the shell ; aperture very large, wide at the base (exposing the co-lumella throughout its entire length) and extending to the apex of the shell, margin reflected only where it joins the pil-lar. Shell polished, of a pale amber colour, extremely thin, with coarse longitudinal striae. This species approaches the L. glutinosus more nearly than any other native Limneus, but from the circumstance of the aperture extending to the apex, has at a cursory view as great a resemblance to the Bulla Akera, Mont., as to any other Bri-tish shell ; a coincidence which is rendered still more remark-able by the columella presenting the same appearance in the L. involutus as it does in that species. The discovery of this new and beautiful mollusk is due to my friend Wm. H. Harvey, Esq. (well known for his botanical investigations) who obtained a few specimens in a small alpine lake on Cromaylaun mountain, near the celebrated lakes of Killarney, in the month of April 1832. The above account was read to the Linnaean Society of Lon-don in April 1834. To the present time (Sept. 1839), I have not heard of the occurrence of the species in any other locality in Ireland. The original station was visited by Mr. R. Ball and myself in June 1834, when we procured only a few small specimens. The time was however unfavourable for seeing these mollusks to any advantage, being at a very early hour in the morning, before the warmth of the sun had tempted them to leave the bottom of the lake or adjoining rivulet. This shell, from partaking more of the form of the marine
V.—Description of Limneus involutus, Harvey, MS. by W. Thompson, Vice-President of the Natural History Society of Belfast;—with an account of the Anatomy of the Animal
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