GASTEROPODA 181 



Family LIOTIIDAE 

 Genus Munditia, Finlay, 1926 

 Type (original designation) : Liotina tryphenensis, Powell 

 Munditia aupouria, n.sp. (Plate L, figs. 3, 4). 



Shell small, discoidal, clathrate, very solid, white. Whorls 3^, very rapidly increasing. 

 Protoconch smooth, of one small planorbid whorl. Post-nuclear sculpture of heavy 

 spiral keels crossed by strong radials. In addition, the whole surface of these whorls is 

 sculptured with a dense pattern of fine somewhat flexuous radiating striae. The spiral 

 keels number six on the body whorl, four of them being much stronger than the other 

 two. The four main keels are equal in strength and spacing and form a broad peripheral 

 band, the upper and lower extremities of which form sharp angles with the flattened 

 spire and base respectively. The fifth and sixth keels are much weaker, one being 

 situated midway between the upper suture and the uppermost peripheral keel and the 

 other midway between the lowest peripheral keel and the umbilicus. The radial ribs 

 are strong medially but become obsolete both towards the upper suture and towards the 

 umbilicus. These radials number fourteen on the body whorl, and where they cross the 

 spirals the points of intersection are produced into spinose nodules. Umbilicus open, 

 perspective, about one-third the major diameter of the base. A series of axial ridges pro- 

 ject into the umbilicus as irregular teeth-like processes. Aperture circular, with a smooth 

 continuous inner margin and a heavy variced finely concentrically striated outer lip. 



Height 1-7 mm.; major diameter 3-5 mm.; minor diameter 2-5 mm. (Holotype). 



Habitat: Off Three Kings Islands, Sts. 933, 934, 260 m. 



Munditia echinata, n.sp. (Plate L, figs. 5, 6). 



Shell very small, discoidal, solid, heavily spinose, white. Whorls 2 J, very rapidly 

 increasing. Protoconch small, of one smooth planorbid whorl. Post-nuclear sculpture 

 of three spiral rows of long spines, which fall into vertical series but are not connected 

 by varices. The middle series of spines at the periphery is much stronger than the other 

 two which occupy the spire and base respectively, both being equidistant from the 

 peripheral series and situated nearer to it than to the sutures. There are twelve vertical 

 series of spines on the body whorl. Surface smooth and polished except for faint axial 

 growth lines. Umbilicus widely open, perspective, less than one-third the major dia- 

 meter of the base. Aperture circular. Peristome thin, slightly expanded, continuous, 

 separated slightly from the parietal wall. 



Height o-6 mm.; major diameter 1-4 mm.; minor diameter 1-05 mm. (Holotype). 



Habitat: Off Three Kings Islands, St. 933, 260 m. 



Distinguished from other members of its genus by the heavily spinose sculpture. 



Munditia manawatawhia, n.sp. (Plate L, figs. 1, 2). 



Shell very small, white, shining, discoidal, solid. Whorls z\, very rapidly increasing. 

 Protoconch small, of one smooth planorbid whorl. Post-nuclear sculpture of strong 



