2G0 opake shelly lamina, the septum between them being of the same thickness and structure ; and between the outer surface of this tube of the siphon and the inner surface of the cylindrical outer sheath or tube, there is deposited at each end of the central septum, between the two siphonal tubes, a transverse space filled with a loose, spongy, cellular shelly texture. Mr. Cuming has two small tubes from California which appear to belong to the genus Teredo, which have the lower or larger end of the tube closed with a single hemispherical cap like those described in my former paper. In one the cap is simple and terminal, and the apex of the tube is oblong and quite simple ; in the other the cap at the lower end of the tube is larger, rather distorted, and bent on one side of the axis of the tube, and the aperture at the apex of the tube is partially divided by a series of plates, which have a promi-nence in the middle on each side, forming an imperfect division of the cavity. I may add, that the siphonal end of the tube being divided into two distinct tubes is not a distinctive character of Furcella, as we have in the British Museum a Teredo or rather a Xylotrya from Sierra Leone which has some of its tubes furnished with two distinct siphonal apertures, and others in which the tubes are only partially separated, and others with a simple aperture. The Cloisonnaine de la Mediterranee of M. Matheron (Annales des Sciences et de 1' Industrie du Midi de la France, vols. I & 2), quoted by Deshayes (Ann. Sci. Nat. xi. 245), is evidently a Teredo, furnished with shelly valves and palettes, and not a Furcella. 6. On a New Genus and several New Species of Uropel-tidjE, in the Collection of the British Museum. By Dr. J. E. Gray, F.R.S., V.P.Z.S., F.L.S., Pres. Ent. Soc, ETC. These animals, when first discovered, were arranged with Typhlops by Schneider ; and afterwards Cuvier, who had previously regarded them as belonging to that genus, formed for some of them a genus under the name of Uropeltis. In the 'Catalogue of the Specimens of Lizards in the Collection of the British Museum' (12mo. 1845), I formed for them a family under the name of Uropeltidce, and di-vided the species into three genera, each containing a single species. Lately I described a fourth genus named Morina in the • Proceed-ings ' of this Society (1858). Professor Johann Muller, in an article on the ' Osteology of Rep-tiles ' in Tiedemann's 'Zeitschrift fur Physiologie' for 1831 (vol. iv.), gave an account of the osteology of the two genera Rhinophis and Uropeltis. Schlegel in 1837 regarded them as a genus under the name of Pseudotyphlops, and noticed three species. Having occasion to re-examine the various specimens which we have received since the printing of the Catalogue above referred to, I have found several additional species.