History of British animals - University of Guam Marine Laboratory

Planorbis. MOLLUSCA. PULMONIFERA. OT118. A. rivalis.— Spire short, pointed;aperture contractedanteally.Bulla riv. Maton and Racked, Linn. Trans, viii. 126. tab. iv. f. 2. Turt>Conch. Diet. 26.— Physa subopaca, Lamark, Hist. Vert. vol. vi. p.2. 157*— In slow streams, rare.Length scarcely half an inch ; pale horn-coloured, glossy; whorls five, thelast occupying fths of the whole length; apex pointed ; aperture with theouter-lip more rounded than the last, and the pillar-lipmore recurved anteallyThis shell was first recorded as having been found in Hampshire, byMr Hay. Dr Turton has seen it alive at Naas, in Ireland. Other localitieshave been mentioned, but they are regarded spurious.— as It is a commonshell from the West Indies.Gen. XXXII. PLANORBIS.— Cavityof the shell entire,sinistral ; the vent, pulmonary cavity, and sexual organs onthe left side ; tentacula filiform.* Whorls rounded on the margin.— 119. P. corneus. —Whorls four, rounded; concave above;mouth suborbicular.Cochlea pulla,List. An. Ang. 143. Conch, t. 137- f. 41—Planorbispurpura, Mull. Verm. ii. 154—Helix cornea, Linn. Syst.i. 1243.Penn. Brit. Zool. iv. 134. Mont. Test. Brit. 449—In ponds and slowstreams. England.Breadth about an inch ; brown, glossylines of ; growth distinct ; whorlsabove, increasing rapidly, and forming a central cavity below, the whorls are;nearly on the same plane, well defined by the separating line ;last whorl projectinginto the cavity of the aperture.When irritated, the animal poursforth a purple fluid from the sides, between the foot and margin of the cloak.The H. nana of Pennant is the young of this species.120. P. spirorbis.— Whorls five, rounded ;flat above ;aperturesuborbicular.Mull. Verm. ii. 161. H. spir. Linn. Syst.i. 1244. Mont. Test. Brit.455, Suppl. tab. xxv, 2—In f. pools.3Breadth about T g ths of an inch ; nearly equally flat on both sides ;of abrown colour ; whorls round, slender, and increasingin size very gradually ;deeplv divided by the separating line ; aperture nearly round, scarcely interruptedby the body-whorl. —This species is stated by Montaguas common inEngland. In Scotland it has occurred to us only in Livingstone Woods,West Lothian-121. P. contortus.— Whorls six, compressed;flat above, concavebelow.Helix con. Linn. Syst.i. 1244—Plan. con. Mull. Verm. ii. 162.—H. con.Mont. Test. Brit. 457. tab. xxv. f. 6.— In pools and ditches, not common.2Breadth about T 5 ths of an inch ;whorls compressed, rounded, even on theupper side, narrow, and deeply divided by the separating line ; beneath, alarge central cavity ; aperture narrow, bent.