Gibbula.] GASTROPODA. 139 



callosity. Columella vertical, arcuate, its expansion completely cover- 

 ing the umbilicus, leaving only a slight pit. Umbilical tract white, 

 impressed. 



Diameter, 4 mm. ; height, 4 mm. (type). Diameter, 7 mm. ; 

 height, 6 mm. (my largest specimen). 



Dentition. Suter, P. Mai. S., ii, 278, fig. in text. 



Type in the British Museum. 



Hob. Lyttelton, on seaweeds in tidal rock-pools, type (H. S.) ; 

 Te Onepoto, near Lyttelton ; Akaroa Harbour (H. S.) ; Lyall Bay. 



Genus '2. FOSSARINA, Adams and Angas, 1863. 



Fossarina, Ad. & Ang., P.Z.S., 1863, 423, pi. 37, f. 9, 10. Type: F. patula, 

 Ad. & Aug. Minos, Hutton, P.L.S. N.S.W., ix, 1884, 369. 



Shell auriform, depressed, narrowly umbilicated ; spire short ; 

 aperture oval, large, and oblique ; interior porcellanous, somewhat 

 iridescent ; peristome continuous ; operculum horny, multispiral, 

 closing the aperture completely. 



The dentition resembles that of Cantharidus. The teeth of the 

 type are figured by Kesteven in Rec. A.M., iv, No. 7, 318, f. 28a in 

 text. 



Distribution. Australasia. 



1. Fossarina rimata, Hutton, 1884. Plate 33, fig. 11. 



Minos rimata, Hutt., P.L.S. N.S.W., ix, 369. Adeorbis (?) Petterdi, Brazier 

 (Fossarina): Hutton, T.N.Z.I., xv. 1882 (1883). 132, not of Brazier. 

 Fossarina, rimata, Hiitt., Index, 83. 



Shell small, depressed, auriform, subperforate, thin, slightly shining. 

 Sculpture consisting of fine microscopical spiral striae, crossed by 

 delicate oblique growth-lines. Colour reddish-brown, the last whorl 

 with a white band around the periphery and 1 or 2 on the base, white 

 zigzag bands or irregular spots above. Epidermis very thin. Spire 

 low, conoidal, outline convex. Protoconch very small, obtuse, of 1^ 

 smooth convex whorls. Whorls 3, very rapidly increasing, convex, 

 the last broadly expanded ; base convex. Suture well impressed. 

 Aperture oblique, very large, broader than high, oval, with a shining 

 but faintly iridescent interior, the colour-markings of the outside 

 distinctly visible. Peristome continuous, outer and basal lip edged 

 by a thin white callus. Columella oblique, arcuate, white. Inner lip 

 covering half of the narrow umbilicus, spreading as a thick, broad cal- 

 losity over the narrow parietal wall, completely uniting the extremi- 

 ties of the peristome. 



Diameter, 5 mm. ; height, 4 mm. 



Dentition rhipidoglossal. 



Type in the Canterbury Museum, Christchurch. 



Hob. Waiwera, type (T. F. Cheeseman) ; Omaha and Matakana 

 (C. Mathews) ; Maloney's Reef (H. S.). 



