aoo DISCOVERY REPORTS 



height of aperture. Post-embryonic whorls smooth, but with a rather flat shoulder, the 

 edge of which carinates the whorls. Aperture narrowly oval, almost vertical. Peristome 

 continuous across parietal wall, slightly thickened and expanded, sharp edged. Columella 

 short and arcuate. Umbilical chink narrow and crescentic. 



Height i"5 mm.; diameter i-i mm. (Holotype). 



Height 1-7 mm.; diameter i-i mm. (Topotype of gradata). 



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



Related to the Snares Islands' N. gradata (Suter, 1908), but more rounded, thinner, 

 without spiral striations, and having a more upright aperture and a shorter spire. 



Notosetia aoteana, n.sp. (Plate LIII, fig. 11). 



Shell minute, ovate-conical, narrowly umbilicate, thin, semi-transparent, white. 

 Whorls four, including a dome-shaped glossy protoconch of 1 h smooth whorls. Spire 

 conical, outlines lightly convex, a little less than height of aperture. Suture impressed, 

 false-margined by the basal part of the preceding whorl showing through. Surface 

 smooth and glossy except for a band of fourteen fine closely spaced spiral striations at 

 the periphery and three rather stronger and wider spaced spiral threads around the 

 umbilical area. Umbilicus very narrow but deep. Aperture rounded. Peristome dis- 

 continuous. Outer lip thin and sharp, inclined slightly forwards above. Columella 

 thickened, arcuate, separated from the base by a groove which runs into the umbilicus. 



Height 1-2 mm.; diameter 1 mm. (Holotype). 



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



Superficially similar to my Lissotesta benthicola (Powell, 1927, Rec. Cant. Mus., in, 

 pt. 2, p. 1 1 15) which also has a peripheral band of fine striations. It is, however, a true 

 member of the Rissoidae, being related to Notosetia neozelanica (Suter), which is similar 

 except that it is larger, imperforate and without the peripheral spirals. 



Notosetia porcellanoides, n.sp. (Plate LIII, fig. 9). 



Shell minute, ovate-conical, thin, smooth, translucent, white. Whorls four, including 

 a small globose protoconch of i\ smooth whorls, the apex slightly tilted. Spire tall, 

 about 1 \ times height of aperture; outlines lightly and evenly convex, nowhere shoul- 

 dered or flattened. Suture linear, shallow, false-margined below. Aperture ovate, 

 almost vertical. Peristome connected across parietal wall by a heavy callus. Outer lip, 

 basal lip and columella thickened slightly. Umbilical chink narrow, crescentic. 



Height 1-35 mm. ; diameter o-88 mm. (Holotype). 



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



This species is most nearly allied to Suter's porcellana, from which it differs in being 

 proportionately smaller, narrower, and without the subsutural shoulder. 



Notosetia subtenuis, n.sp. (Plate LIII, fig. 8). 



Shell minute, ovate-conical, thin, translucent, white, sculptured with exceedingly 

 fine dense spiral striations and equally fine but more distant axial growth lines. Whorls 

 four, including a small bluntly rounded protoconch of i\ whorls, smooth except for 



