Liotia.] GASTROPODA. 151 



1. Liotia polypleura, Hedley, 1904. Plate 33, fig. 16. 



Liotia polypleura, Hedley, Rec. A.M.. v, pt. 2, 1904, 93, f. 20 in text. 



Shell minute, thin, turbinate, widely umbilicate, spire slightly 

 elevate. Sculpture : On the last whorl about 16 thick prominent 

 riblets cross the whorl, slender on leaving the suture ; they slant 

 forward, thickening rapidly, but turning they descend the periphery 

 perpendicularly ; on the base they again bend, and, tapering rapidly, 

 curve into the umbilicus, the margin of which they crenulate ; the 

 interstices are smooth ; on the penultimate whorl the ribs gradually 

 vanish. Colour white. Protoconch of li smooth whorls. Whork 

 convex, 2|, the last descending in front ; base convex. Suture deep. 

 Aperture subquadrate, almost free, peristome formed by one of the 

 ribs. Umbilicus moderately wide, deep. 



Diameter Maj., 0-9 mm. ; min., 0-7 mm. : height, 0-6 mm. 



Type in the Australian Museum, Sydney. 



Hob. Lyall Bay, near Wellington (A. Hamilton) ; Banks Penin- 

 sula (Iredale) ; Bounty Island, in 50 fathoms (Captain Bollons). 



Remark. This species appears to be related to such Australian 

 forms as L. annulata, Ten.-Woods. (Hedley.) 



2. Liotia rotula, Suter, 1908. Plate 33, fig. 17. 



Liotia rot ul a, Suter, P. Mai. S., viii, 24, pi. 2, f. 6. 



Shell small, discoidal, umbilicate, rather solid, translucent, radiately 

 prominently ribbed. Sculpture consisting of distant, elevated, and 

 rounded radiate riblets, much closer together on approaching the 

 aperture. Interstices distantly microscopically spirally striate. Colour 

 white. Spire flat, the apex only slightly raised. Protoconch of 2 

 narrow, smooth, convex whorls. Whorls 4, the last large, convex, 

 the last rounded at the periphery ; base convex. Suture impressed. 

 Aperture circular. Peristome continuous, thickened by the last radiate 

 rib. Columella arcuate, not reflexed. Umbilicus wide, perspective, 

 showing all the whorls. Operculum not seen. 



Diameter, 1-7 mm. ; height, 1 mm. 



Animal unknown. 



Type in my collection. 



Hob. Snares, in 50 fathoms (Captain Bollons). 



Remarks. Allied to L. annulata, Ten.-Woods, from Tasmania, 

 which, however, has the radiate riblets more distant, and lacks spiral 

 striation. L. corona, Hedley, is also nearly related, but it is much 

 smaller, and the radiate riblets are less elevated. 



3. Liotia serrata, Suter, 1908. Plate 33, figs. 18, I8a. 



Liotia xerrata, Suter, P. Mai. S., viii, 23, pi. 2, f. 4. 5 



Shell small, discoidal, rather solid, umbilicated. Sculpture con- 

 sisting of minute fine and slightly wavy radiate riblets ; periphery 



