66 HELIX-ALLODISCUS. 



G. pantherina HUTTON, Trans. N. Z. Inst. xv, p. 135 ; Ibid, xvi, 

 p. 166, 200, t. 9, f. I, t. 11, f. R (jaw and dentition). 



This species has something the aspect of a small Selenites con- 

 cavus, but the surface is finely and densely striated and the shoulder 

 is obtusely angled. 



G. CORDELIA Hutton. PI. 22, figs. 34, 35, 36. 



Shell subdiscoidal, widely umbilicated, striated ; color pale horny, 

 marbled with reddish-brown and covered with a shining yellow 

 epidermis. Spire convex; whorl? 4, slowly increasing, rounded, 

 with tolerably regular, rather crowded, and rather coarse strise of 

 old growth-lines, suture impressed ; umbilicus broad, conical, show- 

 ing all the whorls, but not gradated ; aperture slightly oblique, sub- 

 circular peristome thin, right margin descending, columellar mar- 

 gin rapidly ascending but not vertical, the two margins not 

 approaching. Greatest diameter '32, least '27, height '18 inch. 

 (Butt.) 



Titirangi, Auckland (T. F. Cheeseman). 



G. cordelia HUTTON, Trans. N. Z. Inst. xvi, p. 179 (1884). 



I place this species in Gerontia from the general appearance of 

 the shell, but do not know the animal nor the dentition. It differs 

 from G. pantherina in being more convex, in the epidermis not being 

 plaited, in being more coarsely striated, in the right margin descend- 

 ing, in the aperture being less oblique, and in its colors. (Hutt.) 



My figures were drawn by Mr. Suter from Prof. Button's type. 



Section ALLODISCUS Pilsbry. 



Allodiscus PILS., The Nautilus, Sept. 5, 1892, p. 56, type ff. 

 dimorpha Pfr. Psyra HUTTON, Trans. N. Z. Inst. xvi, p. 201, 

 May, 1884. Not Psyra Stal, 1876, a genus of Orthoptera. 



G. DIMORPHA Pfr. (vol. II, p. 211). 



G. CASSANDRA Hutton. PI. 22, figs. 37, 38, 39. 



Shell depressed, subperforate, closely ribbed ; color pale horny, 

 with longitudinal angulated bands of chestnut. Spire conoidal, 

 depressed, obtuse; whorls 5-1, gradually increasing, very finely 

 ribbed; ribs about 20 in the tenth of an inch ; periphery rounded; 

 suture impressed ; umbilicus very narrow, almost covered; aperture 

 rather oblique, rotundly lunate; peristome acute, straight, the mar- 



