Lymnoea.] GASTROPODA. 607 



lip simple, rather expanded. Columella subcallous, slightly plaited, 

 arcuated. 



Diameter, 5 mm. ; height, 8 mm. : aperture, 4 mm. by 6 mm. 



Dentition (Hutton, T.N.Z.I., xvii, 55, pi. 12. f. 9). Central tooth 

 long and narrow, the reflexed portion small. Laterals bicuspid. 



Type in the British Museum. 



Hab. Auckland (ex Cuming collection) ; confirmed by Gillies. 



Genus 2. AMPHIPEPLEA, Nilsson. 1822. 



Amphipeplea, Nils., Hist. Moll. Suec., 1822, 58. Type : Buccinum glutinosum, 

 Miiller. Buccinum, Miiller, 1774 (hi part). Helix, Gmelin, 1788 (in part). 

 Bulimus, Bruguiere, 1789 (in part). Limneus, Draparnand, 1801. 



Animal short and thick ; the 2 tentacles short, triangular, flat, 

 the eyes at their inner bases ; foot oval, elongate, rounded posteriorly. 

 Mantle well developed, reflexed and partly or wholly covering the 

 shell. Jaw and radula as in Lymnoea. 



Shell broadly oval or almost globular, imperforate, thin and fragile, 

 hyaline, shining ; whorls 3 to 4, rapidly increasing, the last very large, 

 occupying nearly the whole of the shell ; spire depressed ; aperture 

 wide, rotundly ovate ; columella arcuate, with a thin inner lip ; outer 

 lip simple and sharp. 



Distribution. Europe, Philippines, Moluccas, Australasia. 



The animals crawl slowly, and appear to prefer tranquil waters 

 and muddy localities. 



KEY TO SPECIES. 



A. Shell yellowish or greenish, sometimes with a white spiral band 

 on the middle of the body- whorl ; height of spire a little less 

 that half that of the aperture . . . . . . . . ampulla. 



B- Shell dark olive-green to horny-brown ; spire about one-quarter 



that of the aperture in height . . . . . . . . arguta. 



1. Amphipeplea ampulla, Hutton, 1885. Plate 24, fig. 14. 



Limncea (Amphipeplea?) ampulla, Hutt., T.N.Z.I., xvii, 1884 (1885), 55, 

 pi. 12, f. 2. Amphipeplea ampulla, Hedley and Suter, P.L.S. N.S.W. (2), 

 vii, 24 ; Suter, J. de Conch., xli, 1893 (1894), 231. 



Shell ovate, very thin and fragile, seinitransparent. Sculpture 

 consisting of fine plait-like growth-lines. Colour yellowish-horny or 

 greenish, rarely with a white spiral band on the centre of the body- 

 whorl. Epidermis very thin and shining. Spire acute, short, its 

 height less than half that of the aperture. Protoconch globular, with 

 a minute rounded nucleus. Whorls 3|, the last swollen ; base convex. 

 Suture rather deep. Aperture broadly oval, angled above. Outer lip 

 thin, straight, sharp, regularly convex. Columella vertical, slightly 

 arcuate, with a well-marked plait. Inner lip broadly reflected and 

 thickened on the columella, spreading as a thin glaze broadly over the 

 convex parietal wall. 



