602 GASTROPODA. [Pulmonata, 



slope short and straight, right side slope broader and lightly convex, 

 posterior slope concave. Interior polished, the muscle-scar well im- 

 pressed, the siphonal groove usually shallow, but sometimes deeper 

 and broad, the shell with a pronounced bulge on the outside. Margin 

 thin, fragile, slightly membranous. 



Diameter, 16 mm. ; length, 24 mm. ; height, 9 mm. (Antipodes 

 Island). Diameter, 17mm. ; length, 24mm. ; height, 8-5 mm. (Auck- 

 land Islands). Diameter, 13 mm. ; length, 18 mm. ; height, 5-5 mm. 

 (Campbell Island). Diameter, 16 mm. ; length, 21-5 ; height, 7-5 mm. 

 (Macquarie Island). 



Anatomy and Dentition. - - Button. T.N.Z.I., xv, 143, pi. 17, 

 f. N-R ; Studer, Mitth. Naturf. Gesellsch. Bern, 1880, 14. 



Jaw arcuate, tapering to each end ; surface covered with minute 

 papillae. 



Radula having the formula 120x44+1 + 44, laterals about 20. 

 Central tooth very narrow, its length being four times its breadth. 

 Laterals with the cutting-point bidentate and continued down on 

 each side of the cusp ; inner marginals with 2 cutting-points, the 

 inner larger and simply rounded at the end ; outer marginals with 

 3 cutting-points, the median the largest and rounded at the end. 

 (Hutton.) 



Type in the U.S. National Museum, Washington. 



Hob. Antipodes Islands ; Auckland and Disappointment Islands ; 

 Campbell Island (Captain Bollons) ; Macquarie Island (A. Hamilton). 

 Also Tasmania, Kerguelen Land, Patagonia, Strait of Magellan. Falk- 

 land Islands. 



Fam. GADINIID^S, Gray. 



Animal with a distinct, flattened head. Visceral mass conical ; 

 pulmonary cavity aquatic, but without a branchia ; genital orifices 

 separated. Foot flat, thin, simple. There is no jaw. 



Shell conic, patelliform. 



Genus 1. GADINIA. Gray. 1824. 



Gadinia, Gray, Phil. Mag. & Journ., 1824, 63. Type : G. ajra, Gmel. 

 Mouretia, Sowerby, 1835. 



Animal having a circular foot ; pulmonary orifice on the right side 

 near the head, closed by a small lobe. Head large, flattened, divided 

 in front into 2 triangular auriform expansions. No tentacles. Eyes 

 sessile on the sides of the head behind the auriform processes. Male 

 genital orifice near the right eye. Radula with the central tooth 

 usually unicuspidate ; lateral teeth tricuspidate, the median cusp 

 narrow, long, and sharp ; marginals short, bicuspidate. 



Shell obliquely conic ; apex obtuse, subposterior ; aperture orbi- 

 cular, with a small groove directed from the centre to the anterior side 

 of the right margin, tangential to the end of the muscle-scar, which is 



