136 GASTROPODA. [Aspidobranchia. 



B. Umbilicus closed. 



a. Last whorl angled at periphery ; aperture a little higher than 



the spire ; finely spirally lirate, tessellated with white . . Suteri. 

 aa. Last whorl carinate at periphery ; spire higher than the 



aperture . . . . . . . . micans. 



Sect. 1. CALLIOTROCHUS, Fischer, 1880. 



Calliotrochus, Fischer. Icon. Coq. Viv., Trochus. 1880. 417. Type: G. 

 phasianellus, De -\\. 



Shell small, globose, whorls rounded, smooth or spirally striate, 

 thin ; aperture rounded ; outer lip and columella simple, thin, arcuate ; 

 umbilicus narrow. 



1. Gibbula tasmanica, Petterd, 1879. Plate 38, fig. 21. 



Margarita tasmanica, Pett., Journ. of Conch., ii, 103. Gibbula tasmanica, 

 Pett., Man. Conch. (1), xi, 236, pi. 40, f. 20 ; Suter, P. Mai. S., ii, 276. 



Shell small, perforate, globose-turbinate, rather thin, lustreless. 

 Sculpture consisting of fine, regular, close spiral lirae, about 18 on 

 the penultimate whorl, crossed by fine oblique growth-lines. Colour 

 whitish, tinged with yellow, unicoloured, or marked with a few 

 angular radiating maculations of brown. Spire short, outlines convex. 

 Protoconch small, consisting of 2 convex and microscopically spirally 

 striate whorls. Whorls 4J to 6, flatly convex, narrowly shouldered in 

 New Zealand specimens, the last obtusely angular at the periphery ; 

 base convex, impressed around the umbilicus. Suture impressed. 

 Aperture oblique, rounded ovate, angular above, broadly rounded be- 

 low, with a thin iridescent layer of nacre within. Outer and basal lip 

 thin, inside with a narrow white callus. Columella oblique, slightly 

 concave. Inner lip spread out over part of the umbilicus and the 

 parietal wall. Umbilicus narrow. 



Diameter, 5-5 mm. ; height, 6 mm. Diameter, 7 mm. ; height, 

 8 mm. (New Zealand specimen of 6 whorls). 



Dentition unknown. 



Type in the Tasmanian Museum, Hobart. 



Hab. Lyall Bay (A. Hamilton). 



Remarks. The two New Zealand specimens in my collection are 

 distinctly shouldered, and the last whorl is more distinctly angled 

 than in Tasmanian specimens, but otherwise there is no difference. 

 These differences are too slight to separate the New Zealand form 

 as a subspecies. 



jjSect. 2. CANTHARIDELLA, Pilsbry, 1889. 



' Fpantliaridella, Pils., Man. Conch. (1), xi, 197. Type: G. picturata, Ad. & 

 Ang. 



Small forms with much the aspect of tiny Cantharidits ; usually 

 polished, narrowly or not perforate, conical, elongated. 



