Suter. — On Neiu Zealand Mollusca. 251 



mostly young shells. Colour horny, columellar lip broadly reflexed. 

 Dimensions — Shell : length, 7 mm. ; breadth, 4 mm. Aperture : 

 height, 5 mm. ; breadth, 4 mm. Shell : length, 5J mm. ; breadth, 

 4 mm. Aperture : height, 4| mm. ; breadth, 3 mm. 



(2.) Lake Taupo (Stat. 42— With weeds from 20 ft. to 80 ft.).— 

 One specimen collected alive ; yellowish- white, rather slender. 

 The aperture more elongated than in the type. Shell : length, 

 5| mm. ; breadth, 3| mm. Aperture : height, 4 mm. ; breadth, 

 2h mm. 



(3.) Lake Wakatipu (Stat. 10 — Dredged with weeds in 200 ft. 

 to 300 ft.). — One specimen collected alive ; nearly colourless, 

 transparent, very thin and fragile, with broad columellar re- 

 flection ; regular distinct incremental lines. The aperture is 

 longer and narrower than in the type. Shell : length, 5J mm. ; 

 breadth, 3J mm. Aperture : height, 4|- mm. ; breadth, 2J mm. 

 (4.) Lake Wakatipu (Stat. 33— Dredged in 30 ft. to 60 ft.).— 

 Two specimens collected alive. A slender form with elongated 

 aperture, of horn-colour, with regular lines of growth, and the 

 spire a little higher than typical. Shell : length, 5 mm. ; 



breadth, 3 mm. Aperture : 



height, 3| mm. ; breadth, 



2^ mm. Shell: length, 4 mm. ; 



breadth, 1\ mm. Aperture : 



height, 3^ mm. ; breadth, 



If mm. 



^_ N ^ The Dentition.— -Figs. 11-14 



f, — ' represent the most characteristic 



u teeth of the radula of speci- 



12 1A_ mens from the four localities 



Fig. 12 — fig. 11 from Lake Waikare, 



fig. 12 from Lake Taupo, fig. 

 13 from Stat. 10, and fig. 14 

 from Stat. 33, Lake Wakatipu. 

 Compared with Hutton's de- 

 scription and figure of his 

 ' 'S ^ species* a considerable varia- 



bility, especially in the transi- 

 tional teeth, is at once appar- 

 ent. The central tooth shows 

 mostly a second small denticle 

 on the left side ; the lateral 

 teeth have all three cutting- 

 points, but the entocone and mesocone may coalesce, forming 

 only one cutting-point, as was evidently the case in the example 



* Trans. X.Z. Inst., xvii., p. 54, pi. xii., fig. 10. 



Fig. 14- 



