274 DR JOHNSTON'S DESCRIPTIVE CATALOGUE OF THE 



Hob. Slow streams and ponds. In the Tweed and Whiteadder near Berwick, 

 plentiful. 



This shell is plentiful in the marl dug out of peat bogs. When living it is 

 of a pale-greenish horn colour, transparent and marked with a few dark 

 lines which shew the course of the intestine. The animal is white and 

 vivaceous, gliding along the bottom with its tentacula widely spread, the 

 posterior one projecting from under the upper angle of the aperture, or 

 swimming with ease in a reversed position on the surface. Mouth pro- 

 boscidiform, darker : tentacula three, setaceous, lateral : eyes sessile, 

 superior, at the base of the anterior tentacula ; near the posterior tenta- 

 culum there is occasionally extruded an elegant plumose appendage sup- 

 posed to be subservient to respiration : foot transparent white, oblong, 

 wider and rounded behind, in front produced on each side into an acutely 

 triangular process. Operculum horny, with circular striae. 



2. V. cristata, shell depressed, corneous, with four whorls flat above, 

 the base widely and deeply umbilicate exposing the rounded whorls ; 

 aperture circular. Diam. 2 lines. Flem. Brit. Anim. 286. Turbo 

 cristatus, Dillw. Kec. Sh. 883. 



Hob. Ponds. In the Whiteadder near Berwick. 



The animal is strictly aquatic, and never leaves the water even when con- 

 fined to a small vessel. It can creep along the surface with the shell 

 reversed. Behind the two anterior tentacula is a third, as in the pre- 

 ceding species, but the plumose appendage I have not seen, though the 

 animal has been kept for several days together to allow repeated exami- 

 nations. Eyes at the base of the anterior tentacula, rather prominent, 

 with a light areola. Foot bilobed in front, the lobes becoming triangu- 

 lar when fully extended, posteriorly rounded. 



The PALUDINA ACHATINA I have occasionally found on the shores of our 

 bay, having been brought in ballast from the Thames. 



17. TORNATELXA. LAMARCK. 



Shell oval or oblong, with a short rather obtuse spire ; aperture lon- 

 gitudinal, elongated, contracted above and widened below; outer lip 

 simple, acute ; pillar with one or more plaits. 



1. T.fasciata, shell ovate, pale-purplish red, the body marked with 

 two distant white bands and spirally striated ; spire small, coni- 

 cal, of six whorls ; aperture white, the pillar with an oblique fold. 

 Length T ^ths ; breadth ^ths. Lam. Anim. s. Vert. vi. ii. 220. 

 T. tornatilis, Flem. Br. Anim. 336. Voluta tornatilis, Dillw. 

 Rec. Sh. 503. 



Hab. Berwick Bay, very rare. 



The strise are much stronger and wider apart at the base of the shell. 



18. STYLIFER. BRODERIP. 



Shell thin and transparent, spiral with a produced apex ; aperture 

 somewhat ovate, narrowed above, with an acute sinuated lip : no oper- 

 culum. Zoophagous. 



