I?6 DISCOVERY REPORTS 



Height 1-05 mm.; diameter i-omm. (Holotype). 

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



This species appears to be more nearly allied to the Tasmanian S. ornata, May, than 

 to any of the New Zealand species. 



Genus Schizotrochus, Monterosato, 1877 

 Type : Scissurella crispata, Fleming 



Schizotrochus aupouria, n.sp. (Plate XLIX, fig. 3). 



Shell small, depressed trochiform, very thin, narrowly umbilicate, white. Spire low, 

 gradate, about one-third height of aperture. Besides the usual sharp double keels en- 

 closing the deep narrow anal fasciole there are two rounded keels on the middle of the 

 base. These are separated by a shallow depression only, making them appear as one 

 broad spiral fold. Whorls 3 \, including a smooth planorbid protoconch of i\ whorls 

 followed by a brephic stage of four sharp radials. Post-nuclear whorls sculptured with 

 exceeding fine and crowded sharp radial riblets, those on the base being flexuous where 

 they cross the keels. Umbilicus small, overhung by the thin reflected inner lip. In the 

 sloping concavity leading to the umbilicus there are a few indistinct spiral striations. 

 Aperture diamond-shaped. Peristome thin, continuous, except for the deep anal slit 

 which runs back over nearly half the body whorl. 



Height 0-9 mm.; diameter 1-25 mm. (Holotype). 



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



This species is not the juvenile of S. mantelli (Woodward, 1859) (= S. regia, Mes- 

 tayer, 19 16). Series of both species have been examined, showing that mantelli at all 

 stages has an evenly convex base, whereas aupouria always has the heavy bicarinate 

 basal fold. 



Schizotrochus finlayi, n.sp. (Plate XLIX, fig. 2). 



Shell small, depressed trochiform, very thin, narrowly umbilicate, white. Spire low, 

 gradate, about two-thirds height of aperture. Peripheral double keel strong with sharp 

 lamellar edges. Sculpture of crisp lamellar radials, those on the base being finer and 

 much more closely spaced than those above. The radials number twenty-two on the 

 upper surface and about sixty on the base. Interstices crowded with fine spiral lirations, 

 there being about twelve between the suture and the peripheral keels. 



Height 17 mm.; diameter 1-9 mm. (Holotype). 



Habitat: Off Three Kings Islands, St. 934, 92 m. 



This makes the third Recent species of the genus found in New Zealand. The dis- 

 tinctive character of finlayi is the discrepant sculpture, few wide-spaced radials above 

 and much more numerous finer radials below. 



