524 Mr. IT. B. Preston on new 



Allenoconcha matheivsi, sp. n. 



Shell depressedly turbinate, pale yellowish brown ; 

 whorls 5, regularly increasing, the last angled at the peri- 

 phery, microscopically sculptured with very fine, slightly 

 wavy, closely set, spiral striae; suture impressed, very 

 narrowly, callously margined below ; columella margin a 

 little reflexed above, very obbquely descending in a slight 

 curve, a well-defined, light, parietal callus joining it with the 

 upper margin of the labrum ; labium simple ; aperture 

 obliquely subcrescentic. 



Alt. 2*25, diam. maj. 4*75, diam. min. 4'25 mm. 



Bab. Ball's Bay, Norfolk Island (R. Bell) ; also taken by 

 Mr. Bell on Mount Pitt and at Steel's Point. 



Allenoconcha mons-pittensis, sp. n. 



Shell perforate, small, depressedly orbicular, polished, 

 shining, yellowish brown, shading in the subsutural region 

 to greyish ; whorls 5, flattened, regularly increasing, the 

 last sharply angled at the periphery, marked with indistinct, 

 radiate, transverse growth-plicae, crossed by very fine, micro- 

 scopic, closely set, wavy, spiral striae, which become almost 

 obsolete on the base of the shell; suture lightly impressed, 

 narrowly margined below ; perforation very narrow, almost 

 covered by the flattened and rather hooked outward expansion 

 of the basal parietal callus ; columella margin interiorly 

 thickened into a broad, excavately arched, pillar-like callus 

 which extends both interiorly and exteriorly as a basal 

 parietal thickening ; labrum acute, projecting in front of the 

 pillar-like columella callus ; aperture obliquely and rather 

 compressedly sublimate. 



Alt. 1*5, diam. maj. 4*25, diam. min. 3 - 75 mm. 



Bab. Mount Pitt, Norfolk Island (R. Bell). 



Allenoconcha perdepressa, sp. n. 



Shell small, very depressed, somewhat iridescent, corneous ; 

 whorls 4, regularly increasing, the last angled at the peri- 

 phery, marked with radiate transverse plica?, and sculptured 

 with exceedingly fine, closely set, microscopic, spiral striae ; 

 suture impressed, narrowly margined below; columella 

 margin very obliquely descending; labium simple; aperture 

 obliquely and very compressedly and broadly subluuate. 



Alt. T25, diam. maj. 3*25, diam. min. 3 mm. 



Bab. Mount Pitt, Norfolk Island (R. Bell). 



