774 GASTROPODA. [Pulni.onata. 



gularly and rugosely plicated, the plicae, by anastomosing, forming a 

 partial network, and inclined backward in the same direction as the 

 incremental lines, which are at intervals more or less conspicuous on 

 the last whorl. Colour most likely fuscous, but only specimens devoid 

 of cuticle have hitherto been found. Spire depressed conoidal, slightly 

 convex, obtuse. Protoconch slightly raised, of If whorls, finely ob- 

 liquely plaited. Whorls 4^, rapidly increasing, the first ones convex, 

 the last bluntly keeled at the periphery, above which, at a distance 

 of about 2 mm., is a revolving rib, separated from the keel by a shallow 

 groove, and from the slightly raised ridge below the suture by a broad 

 depression ; this ridge disappears gradually on the penultimate whorl ; 

 base flatly convex. Suture sharply impressed, subcanaliculate near 

 the aperture. Aperture obliquely transverse, subtriangular, the mar- 

 gins slightly approximating and united by a callus on the parietal 

 wall. Outer lip sharp, slightly depressed and advancing above, angled 

 at the periphery, and receding below. Columella oblique, arcuate. 

 Inner lip slightly thickened and reflected. Umbilicus deep, infundi- 

 bular, about one-third of the greatest diameter, margined by a slightly 

 elevated ridge. 



Diameter Maj., 24 mm. ; min., 20 mm. : height, 12 mm. 



Embryonic shell subglobose, the upper side flat and radially pli- 

 cated, with a distinct shallow umbilicus. Diameter. 3-5 mm. ; height, 

 2-5 mm. 



Animal unknown. 



Type in my collection. 



Hob. Cape Maria van Diemen, type (McGahey) ; Te Reinga 

 (C. Cooper). 



5. Rhytida Greenwood!, Gray, 1850. Plate -tit, fig. 12. 



Helix Greenwoodi, Gray, P.Z.S., 1849 (1850), 165; A.M.N.H. (2), vii, (55; 

 Conch. Icon., vii, pL 81, f. 434 ; Conch. Cab. (2), i, pt. 2, pi. 107, f. 11-13 ; 

 M.H. Viv., iii, 156 ; Hector, Cat. Land Shells N.Z., 16 ; Zeitschr. f. 

 Malak., 1850, 86 ; M.N.Z.M., 16. Rhytida Greenwoodi, Gray : Button, 

 T.N.Z.I., xvi, 208; Man. Conch. (2), i, 12(i, pi. 24, f. 74; Hedley and 

 Suter, P.L.S. N.S.W. (2), 630: .Suter, J. de Conch., xli, 284. Helix 

 Gunni, Gray, MS. 



Shell convexly depressed, urnbilicated, rugose, thinnish, slightly 

 shining, fuscous. Sculpture consisting of radial oblique wrinkle- 

 scrise, partly anastomosing and forming an irregular network of 

 elongated narrow meshes ; at the periphery there are usually 5 to 6 

 distant rounded but slightly raised spiral ribs, which are sometimes 

 interrupted or anastomosing. Colour fuscous with an olive-green 

 tinge. Epidermis thin, very lightly shining. Spire not high, obtuse, 

 broadly convex. Protoconch of 1| radially striate turns, flattish, but 

 slightly elevated above the next whorls. Whorls 4|, rather convex, 

 rapidly increasing : periphery narrowly rounded : base convex, sub- 



