OCR Text |
Show 128 DR. GWYN JEFFREYS ON THE MOLLUSCA OF THE [Feb. 19, 1. HYDROBIA ULV^E, Pennant. Turbo ulva, Penn. Br. Zool. iv. p. 132, pi. lxxxvi. p. 120. Hydrobia ulva, B. C. iv. p. 52; v. p. 208, pi. lxix. f. 1. 'Porcupine' Exp. 1869: St. Donegal B. (type and vars. barleei and octona), 19 (var. barleei), 58 (same variety). 1870 : Med. 50 (var. subumbilicata). Distribution. Everywhere between tidemarks and in brackish water throughout the eastern portion of the North Atlantic, from Finmark and Novaia Zemblia, southwards to the Mediterranean and Adriatic; California (P. Carpenter) ? A chance specimen of the variety barleei was dredged in the Bav of Biscay during the ' Travailleur' Expedition of 1880 at the depth of 1062 fathoms! Fossil. Pliocene and Post-tertiary : Scandinavia, Great Britain and Ireland (including the Coralline, Red, and Mammalian Crags), Leghorn, Southern Italy, and Rhodes. This abundant and widely distributed little shell has long served as a manufactory of nearly countless species; and even undistin-guishable and useless genera, such as Peringia and Peringiella, have been invented to show the ingenuity of ambitious concho-logists. Assiminea gallica of the late Dr. Paladilhe is another synonym, as I have ascertained from the inspection of typical specimens which that author kindly sent me. Turbo minutus of Totten, which inhabits similar situations on the western coasts of North America, and which I found plentifully on the seaboard of Canada and New England, appears to be a different species. See also ' British Conchology' for synonyms and varieties. 2. HYDROBIA COMPACTA \ Jeffreys. (Plate IX. fig. 9.) S H E L L conical, thick, semitransparent, and glossy : sculpture none, except in the periphery being obtusely angular : colour yellowish : spire rather short, bluntly pointed : whorls 6, flattened, gradually increasing in size ; the last occupies about two thirds of the spire when viewed in a supine position : suture slight hut distinct: mouth oval, contracted above and angular below : outer lip somewhat thickened: inner lip also thickened, and reflected on the pillar : peristome continuous : base imperforate. L. 0*175. B. 0 1. 'Porcupine' Exp. 1870: Atl. St. Tangier B. Several dead specimens. Differs from H. ulva in its shape, which is that of a short cone, in the periphery being angular or keeled at all stages of growth, and in the base being imperforate. I cannot identify the present species with any of those which were described and figured by Paladilhe in his ' Nouvelles Miscellanees Malacologiques.' Much confusion seems to have been caused by him and other continental writers, not only in making so many worthless genera of this family (Lit-torinidoz), but in referring species of Hydrobia to Assiminea, which belongs to the Pulmonobranchiata. For instance, in describing his Assiminea obeliscus (which is apparently one of the numerous Compact. |