84 



MOLLUSCA. 



Vermetus. 



Genus XXXIX.— VERMETUS— JrfansoK. 



Shell thin, tubulose, loosely spiral in the lower portion, 

 three or four upper volutions regularly spiral ; adherent 

 to extraneous substances by the apex of the spiral part ; 



Shell smooth ; spiral portion depressed above, and concave 

 beneath; three or four volutions, united at the sides by a spiral 

 projection ; prolonged portion always at least double the dia- 

 meter of the spiral part in length ; tube rounded throughout. 



Found in the Greensand at Dilton, near Westbury, and in 



aperture orbicular; margins united, and provided with ^^^ ^^^^j. Greensand of Dorsetshire, 



an operculum. 



1. V. BoGNORiENSis The Bognor Vermetus, pi. XLIII. 



fig. 1. 



Vermetus Bognoriensis. Sowerby, Min. Conch. VI. p. 194, 

 pi. 596, fig. 1, 2, 3. Vermicularia Bognoriensis, Mantell, Geo. 

 of Sussex, p. 272. Serpula? Parkinson, Org. Rem. III. p. 



97, pi. 7, fig. 8. 



The spiral portion smooth, circular, conical, and concave 

 beneath ; tube obscurely pentangular, with a furrow above and 

 below ; the tubular projection cyhndrical, slightly curved, and 

 generally exceeding in length the longest diameter of the shell. 



This species is gregarious, and is plentiful in the Sandstone 

 of the Bognor Rocks, and on the coast of Sheppy, as well as at 

 Highgate Hill. Dr. Mantell mentions a block of Sandstone in 

 his possession, about four inches square, which contains nearly 

 twenty specimens lying in relief. 



2. V. poLYGONALis. — The Polygonal Vermetus, pi. XLIII. 



fig. 2. 



Vermetus poli/gonalis. Sowerby, Min. Conch. VI. p. 196, 



pi. 596, fig. 6. 



Spiral portion in the form of a short cone, provided with one 

 involute, prominent, erect ridge, which wind to the apex, and 

 two less elevated ridges round the margin, where they ter- 

 minate more prominently, and their points ending in two short 

 spines; tubular projection, having a trumpet-shaped termina- 

 tion, and with seven acute angles. 



Found at Seabrook, in Limestone belonging to the Lower 

 Greensand series. 



3. V. coNCiNNUS The Trim Vermetus, pi. XLIII. fig. 3. 



Vermetus concinnus. Sowerby, Min. Conch. VI. p. 195, pi. 



596, fig. 5. 



Shell circularly convolute, slightly convex on one side, and 

 concave on the other, a great portion of the tube projecting; 

 tube pentangular, four of the angles acute, and the other rather 

 obscure. 



Found plentifully in a brown Sandy Limestone in Robin 

 Hood's Bay, Isle of Wight. 



4. V. TUMIDUS. — The Tumid Vermetus, pi. XLIII. fig. 



4,5. 



Vermetus tumidus. Sowerby, Min. Conch. VI. p. 195, pi. 

 596, fig. 4. 



Shell thick, discoidal ; with few volutions, seldom exceeding 

 two ; tube thick, externally marked with a broad, concentric 

 furrow or two on the sides; prolonged portion small, short, and 

 cyhndrical; margin of the aperture thickened; apex with a 

 callus. 



Found in the Coral Rag at Scarborough. 



5. V. coNCAVus. — The Concave Vermetus, pi. XXXVII.* 

 fig. 40. 



Vermetus concavus. J. do C. Sowerby, Geo. Trans. IV. 

 2nd series, p. 343, pi. 18, fig. 10. Fitton, lb., p. 228. Ver- 

 micularia concava, Sowerby, Min. Conch. I. p. 125, pi. 57, figs. 

 1 to 5. 



STRIATES. — The Striated Vermetus, pi. XLIII. fig. 



Couch. II. p. 92, pi. 



6. V 

 14, 15. 



Plano7'bis radiatus. Sowerby, Min. 

 140, fig. 5. Fleming, Brit. An. p. 279. 



Shell strong ; with the spiral portion of the volutions nearly 

 lenticular, considerably produced, and nearly concealed in the 

 lower side ; both sides traversed by radiating strife, which are 

 sharp and acute in and near the umbiUcus, but gradually 

 become obsolete towards the back of the volutions; under side 

 umbilicated; aperture orbicular, swelling at the margins; thick- 

 ness about a fourth of its diameter. 



Found in the Greensands of Blackdown, Devonshire. 



FAMILY III.— PLICACEA. 



Shell with the aperture somewhat contracted, and the 

 columella plaited. 



Genus XL— TORNATELLA.— Zo;«arc;i. 



Shell oval or oblong, cylindrical, generally grooved or 

 striated; spire very short, and somewhat obtuse, in a few 

 species acute ; aperture longitudinal, elongated, not less 

 than half the length of the shell, but frequently two- 

 thirds, straitened above, and somewhat widened below ; 

 outer lip simple, with an acute edge ; inner lip thin, and 

 but slightly reflected over the body ; columella, which is 

 spiral, thickened, plaited, its base confluent Mith the 

 outer lip. 



1. T. ACUTUs. — The Acute Tornatella, pi. XLIII. fig. 6, 

 7, 8. 



Tornatella acutus. Fleming, Brit. An. p. 336. Acteon 

 acutus, Sowerby, Min. Conch. V. p. 78, pi. 455, fig. 2. 



Shell subcylindrical, smooth; spire short, conical, and acute; 

 columella provided with one plait; aperture about three-fourths 

 the length of the shell. 



Found in the Oohte at Ancliffe. 



Fig. 7, natural size ; 6 and 8, magnified. 



2. T. No^ Noah's Tornatella, pi. XLIII. fig. 9, 10. 



Tornatella Noce. Fleming, Brit. An. p. 336. Acteon Noce, 



Sowerby, Min. Conch. IV. p. 101, pi. 374. 



Shell oval, fragile, subcylindrical ; with one large plait at the 

 base of the columella ; aperture oblong-ovate, straitened, and 

 pointed above, much widened and rounded below ; outer lip 

 sulcated within ; whole surface covered with numerous, equi- 

 distant, transverse strise, and obscurely decussated by longitudi- 

 nal stria;. 



Found in the Crag at Walton, Essex. 



