258 Transactions. — Zoology. 



Art. XIV. — The First-discovered New Zealand Gundlachia. 



By Henry Suter. 

 [Read before the Wellington Philosophical Society, 1th September, 1904.1 



Gundlachia neozelanica, n. sp. 



Ancylus, sp., Suter, Journ. de Conch., vol. xl., pp. 248-250 

 (1892). Ancylus tasmanicus, Suter, P.L.S. N.S.W. (2), 

 vol. vii., p. 624 (1893), (not of T.- Woods). Gundlachia, 

 sp., Suter, Trans. N.Z. Inst., vol. xxvi., p. 122, pi. xiv., 

 figs. 1-5 (1894); Gundlachia, sp., Suter, P.L.S. N.S.W. 

 (2), vol. viii., p. 486 (1894) ; Gundlachia, sp., Hedley, I.e., 

 pp. 505, 507, 511, pi. xxiv., figs. 12-15 ; Gundlachia, sp., 

 Suter, Journ. de Conch., vol. xli., p. 229 (1894). 



Shell depressed-conoidal, oval-oblong, thin, subtransparent, 

 horn-colour, with a blackish-green coating ; apex a little inclined 

 to the right, situated at the posterior sixth of the length, flatly 

 convex anteriorly ; concentric lines of growth at regular inter- 

 vals. Interior light-brown, shining ; aperture elongated-oval, 

 slightly broadened anteriorly. Length, 3 mm. ; breadth, 2 mm. ; 

 height, | mm. 



Hob. River Avon, near Christchurch. 



Type in my collection. 



With regard to the dentition I have to rectify a mistake 

 in the figure : the rhachidian tooth is bicuspid, not tricuspid. 



The formation of a septum has been described and figured 

 by Hedley (I.e.) from specimens I sent him. 



I always hesitated giving this species a name, as I hoped 

 fully developed specimens might turn up. This, however, has 

 not been the case, and, as a second species has been discovered, 

 it is incumbent to name the first-discovered form. 



Art. XV. — Revision of the New Zealand Species of the Genus 

 Potamopyrgus, with Description of a New Species. 



By Henry Suter. 



Communicated by A. Hamilton. 



[Read before the Wellington I'hilosophical Society, 1th September, 1904.] 



A revision of the New Zealand Hydrobiino3 was published by 

 Captain F. W. Hutton in 1882,* reducing the already described 



* Trans. X.Z. Inst., vol. xiv., pp. 143-146, pi. i., figs. A-H. 



