^4 DISCOVERY REPORTS 



Height 1-05 mm.; major diameter 1-45 mm. (Holotype). 



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



This species bears an extraordinary resemblance to Argalista rotella, n.sp., described 

 herein from the same dredge station. Shape, size, umbilicus and basal radial folds are 

 closely similar in both species, but paradoxa has the characteristic continuous peristome 

 of Cirsonella and dense microscopic spiral striations, while rotella has a discontinuous 

 peristome with a thin edge, overhanging above as typical of Argalista, as well as fewer 

 and stronger spiral striations. 



Cirsonella pisiformis, n.sp. (Plate L, figs. 13, 14). 



Shell small, white, solid, turbinate, umbilicate. Spire about two-thirds height of 

 aperture. Whorls 3 J, including a typical smooth low convex protoconch of one whorl. 

 Post-nuclear whorls smooth except for dense extremely fine and inconspicuous striations. 

 Width of umbilicus about one-seventh major diameter of base. Outer edge of umbilicus 

 crenulated by fourteen short stout radial folds ; within there is a spiral cord which curves 

 outwards and downwards joining the lower part of the inner edge of the peristome. 

 Aperture circular. Peristome continuous, slightly thickened and separated by a groove 

 from the parietal wall. 



Height 1-3 mm.; major diameter 1-45 mm. (Holotype). 



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



This species differs from paradoxa in being more globular in shape and in having a 

 much narrower umbilicus. 



Cirsonella laxa, n.sp. (Plate L, figs. 8, 9). 



Shell minute, white, moderately solid, discoidal, widely umbilicate and loosely coiled. 

 Whorls 2§, plus a smooth low convex protoconch of 1 \ whorls. Spire not raised above 

 the body whorl. Coiling rapid, latter half of body whorl bent slightly downwards. 

 Sculpture of indistinct spiral cords, crossed by microscopic axial lines of growth. There 

 are five spiral cords on the penultimate whorl, and five on the base that are considerably 

 stronger than the rest. These five stronger basal cords extend from in front of the suture 

 to the edge of the umbilicus. The wall of the umbilicus is smooth and the remainder of 

 the body whorl, apart from the five cords, is crowded with closely spaced fine spiral 

 threads. Umbilicus wide, perspective, about one-third the diameter of the base. 

 Aperture circular. Peristome continuous, slightly thickened, actually detached from 

 the parietal wall, and strongly recurrent at the suture. 



Height o-8 mm.; diameter 1-25 mm. (Holotype). 



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



This species is characterized by its loose coiling, discoidal shape, aperture recurrent 

 at suture, and lack of umbilical crenulations. 



Cirsonella waikukuensis, n.sp. (Plate L, figs, 10, 11). 



Shell minute, white, solid, depressed turbinate. Spire about half height of aperture. 

 Whorls three, including a typical smooth low convex protoconch of one whorl. Post- 



