294 STUDIES ON AUSTRALIAN MOLLUSCA, xi., 



This evidence seems opposed to the occurrence of this species in 

 Australia. The Australian shell doubtfully referred to C. regulare 

 by Carpenter is here illustrated fig. 70. 



Bivona constrictor Morch. 

 (Plate xviii., fig. 71.) 

 Bivona constrictor Morch, Proc. Zool. Soc, 1862, p. 63. 

 In the British Museum is a single specimen, perhaps type, but 

 not so marked, labelled, "Bivona constrictor, Morch, Australia, 

 M.C." This is illustrated in the accompanying figure. 



Stephopoma tricuspe Morch. 

 (Plate xix., figs. 72, 73, 74.) 



Stephopoma tricuspe Morch, Proc. Zool. Soc, 1861, p,150, PL 35, 

 fig. 1. 



In the British Museum are two tablets, perhaps types, but not 

 so marked, labelled "Stephopoma tricuspe, Morch, c.operc. et foeti, 

 Australia, M.C." From these have been derived figures of a mass 

 of tubes (fig. 72), and of the operculum (figs. 73-74). No Labitat 

 for the species has been published; it lives in Sydney Harbour. 



Naricava, gen.nov. 



A genus related to Vanikoro, but differing by smaller and thinner 

 shell, by fewer, more depressed and rapidly increasing whorls, and 

 by the last whorl being expanded horizontally. Naricava holds 

 somewhat the relation to Vanikoro, that Sigaretus does to Euna- 

 ticina. Type, Adeorbis angasi A. Adams, 1863. Other Australian 

 species are, Adeorbis vincentiana Angas, 1880; Adeorbis angulata 

 Hedley, 1905 ; and Adeorbis kimberi Verco, 1907. Probably Adeor- 

 bis platymna Tomlin, 1913, from Singapore, belongs here. 



Naricava is perhaps related to Laciniorbis* but that does not 

 seen to have the peculiar apex of Naricava, nor is it referred to the 

 Vanikoridse. It has been indicated by Iredale,f that Adeorbis may 

 be replaced by Tornus, but this is not established. Verril classifies 

 Adeorbis near Rissoa. 



* v. Marteus, Archiv Naturg., lxiii.,(l) 1897, p.175. 

 flredale, Proc. Malac. Soc, ix., 1911, p.259. 



