Mollusks. 7355 



five, swollen, with a deep suture. Length b\ lines, breadth 2^ to 3 lines. 

 Mouth occupying about half the total length. Pillar-lip twisted, the 

 swelling body-whorl projecting into and contracting the mouth above. 

 A distinct narrow umbilical chink, formed by the reflexion of the pil- 

 lar-lip upon the columella. 



The above description, which applies, not to the ordinary form of 

 P. acuta as found on the Continent, but to the variety y. minor of 

 Moquin-Tandon, is drawn up from examples of the Kew Physa for- 

 warded to me by Mr, Choules. The locality from whence the species 

 is presumed to have been introduced into the Kew Gardens, and 

 which is several miles distant from the latter, has been communicated 

 to me, and having examined specimens from thence, and satisfied 

 myself of their identity, I see no grounds for doubting the indige- 

 nousness of Physa acuta in that habitat. 



Physa fontinalis, Linneus. 



Animal. — Mantle-margin extensile and reflected on the shell ; digi- 

 tations large, flat and numerous, viz., five or six behind, enwrapping 

 and surmounting the apex of the spire ; and five to eight on the 

 columella, extending half round the body, and distinctly visible when 

 the animal is viewed from above. Foot longer than the spire. Ten- 

 tacles tapering to their extremities, pale. 



Shell ovate, with a blunt apex, thin, fragile, transparent, horn- 

 coloured (rarely white). Whorls three and a half to four and a half, 

 their suture shallow. Length 4| lines, breadth 2f lines. Mouth oc- 

 cupying four-fifths of the total length. Pillar-lip scarcely twisted. 

 No umbilical chink. Outer lip forming an acute angle by its junc- 

 tion with the body, and descending direct from the suture. 



For some years I have had a Physa in my cabinet which would 

 seem to be specifically distinct from all yet described ; and I take 

 this opportunity of drawing attention to the form in the following 

 description : — 



Physa ? 



Shell subquadrangular-ovate, with a very blunt apex. Body-whorl 

 greatly swollen, and mouth widely expanded. The outer lip forming 

 a right angle at its junction with the body, and projected a short dis- 

 tance directly outwards before the downward slope commences. 

 Whorls three and a half. Length 5^ lines, breadth 3| lines. Mouth 

 occupying six-sevenths of the total length. 



