54 Transactions,— Zoology, 
Art, VI.—The Freshwater Shells of New Zealand belonging to the Family 
Limneide. By Professor F. W. Hurron. 
[Read before the Philosophical Institute of Canterbury, 5th June, 1884.) 
Plate XII. 
Tue New Zealand Limneide are not very numerous in species although 
they are usually very variable. Limnea is rare, or abundant only in a few 
localities. Aplexa is far more common, but not nearly so abundant as 
Potamopyrgus. Our single species of Planorbis is so small it may easily be 
overlooked, but it does not appear to be common. I have to thank Mr. 
H. M. Gwatkin for sending me odontophores of the British Limneide 
without which I should have hesitated to name some of our species. 
Luma (ÅMPHIPEPLEA) ARGUTA, Sp. nov. PI. xii., fig. 1. 
Shell globosely ovate, glossy horn brown when dry, dark olive caen 
when alive; rather strongly longitudinally striated, and without amy spiral 
lines. Whorls 3 or 84, the last inflated, spire very short, slightly acute, 
usually eroded at the apex, suture moderate, simple. Aperture large, ovate, 
occupying three quarters of the entire length of the shell; columella 
arcuate, with a well-marked spiral fold; inner lip reflexed over the 
umbilical region, and connected with the lip above by a thin white callosity. 
Length :8; diameter :18 ; aperture, long :24, broad :17 inch. 
Hab. River Avon, Christehurch. 
Animal olive brown sparingly speckled with yellowish white. Edge of 
the mantle simple, slightly reflected over the shell. Foot broad and 
rounded behind ; tentacles short, flat, triangular, with the eyes at the 
inner bases. 
Dentition (pl. xii., fig. 10), 231-23, of which about 9 are laterals. Central 
tooth slightly broader behind, the length rather more than twice the 
greatest breadth; the reflexed portion short, with a minute cutting point. 
Laterals with the reflexed portion nearly as long as the base, triangular, 
slightly sinuated on the inner and notched on the outer side. Cutting 
points two, the inner one large, the outer small. The large cutting point 
is simple in the inner laterals, but carries a small denticle in the outer 
ones. Marginal teeth from three to many dentate, getting longer and 
narrower outwards. Length of the radula rather more than twice its 
breadth. Transverse rows of teeth nearly straight. 
Ova attached to stones or water plants in gelatinous lumps of 10-20 
together. 
This species much resembles L. glutinosa of Europe, but in that species 
the mantle is represented as eovering nearly the whole of the shell. I have 
not been able to compare the dentition, 
