150 GASTROPODA. [Aspidobranchia. 



Aperture rounded. Outer lip thick, toothed within. Columella sub- 

 vertical, straight, with a tubercle at its base, followed by 2 notches 

 and 2 or 3 teeth on the basal lip. Umbilicus narrow but deep, the 

 basal lip continued as a rib and descending into the umbilicus. 

 Operculum unknown. 



Diameter, 6 mm. ; height, 6 mm. 



Dentition unknown. 



Type in the Dominion Museum, Wellington. 



Hob. Wellington. 



Remarks. Pilsbry remarks : ' May prove the same as E. tas- 

 manicus, T. -Woods." Tate and May make the latter a synonym of 

 E. scabnusculus, Angas, which is the type of section Herpetopoma, 

 Pilsbry, having a multispiral operculum. The latter species has usually 

 a much coarser sculpture, the spiral lirae are less numerous, the um- 

 bilicus is not so deep and partly covered by the inner lip. As the 

 operculum of E. Hamiltoni is unknown, it is impossible to say whether 

 the two species are really so nearly allied as the shell-characters would 

 indicate. 



Fam. LIOTIID^, Gray. 



Animal with the head proboscidiform, epipodial line with a pair 

 of conical lobes and 3 pairs of cirri. Dentition similar to that of 

 Delphinula, Turbo, and Astrcea, with 5 lateral teeth. Jaws present. 



Shell turbiniform or discoidal, white, with longitudinal ribs or 

 clathrate ; aperture feebly nacreous ; peristome continuous, thick, 

 with a callous varix ; operculum multispiral, hispid, corneous, with 

 a calcareous layer formed of pearly particles spirally disposed. 



Genus 1. LIOTIA, Gray, 1847. 



Liolia, Gray, Syn. Brit. Mus.. 1840 (no description) ; P.Z.S., 1847, 145. 

 Type : Delphinula cancellata, Gray. 



Characters those of the family. Gray's type was a cancellated 

 species, and the genus Liotia, in the most restricted sense, will comprise 

 those species which have numerous varices or radiating circumambient 

 ribs cancellated more or less by spiral sculpture. (Dall.) 



Distribution. Tropical and subtropical seas. 



Fossil. Lias and Eocene. Not known to occur fossil in New 

 Zealand, but in Australia. 



KEY TO SPECIES. 



A. Shell fcurbinate, with axial riblets . . . . . . volt/pleura 



B. Shell discoidal. 



a. With radial riblets. 



l>. Riblets strong, the interstices microscopically spirally 



striate . . . . . . . . . . ,-otnhi. 



bb. Riblets very fine, periphery serrate . . . . strrata. 



aa. Without radial riblets, a few folds at suture and umbilicus, 



2 keels produced into processes at the peristome . . solitarin. 



