123 



higlily polished. It is yellowish white, and the apical whorls 

 are livid. Blacknian's Bay, Tasmania. W. F. Petterd. 



RissoiNA UNiLlRATA. T. mviiuta, pyramidata, alba nitente, opaca 

 vel siihpellucida, anfr. 5, in spira conspicue carinatis, ultimo anfr. 

 generatim Icevi, aliquando unicarinato, semper autem ad labrum late 

 inflatoque ; apice obtuso, nucleo 1^ anfr. ; apertura circulari, labro 

 producto, labio rejlexo, sutura profunda, unilirata et marginata. Long. 

 1^ ; 2| mil. ; lat. h, circiter longitud. Blackman's Bay. W. F. 

 Petterd. 



A minute white shell with a conspicuous inflation on the 

 outer lip, and a fine thread which forms a single or double 

 keel on the upper whorls. The last whorl is generally, but 

 not always destitute of these threads, or has only one. The 

 suture has also a thread and is margined. One larger speci- 

 men has only one angle in the whorls, which is the result of 

 the one thread-like line proceeding from the last whorl. The 

 shell appears to be variable. 



BiTTiUM MINIMUM. T. minuta, tumide-pyramidata, badia saturata ; 

 nitente; anfr. 7, planatis, regulariter crebre costatis, costis granosis 

 et lineis tribus granorum spiraliter cinctis ; costis ex serie granorum 

 confectis ; sutura acute impressa ; apice decollato, apertura late 

 elliptica, canali brevi obliquo, basi striata tantum, labro simplici, 

 columella incrassata tortuoso. Long. vix. 3 mil. ; lat. 1. Blackman's 

 Bay. W. F. Petterd. 



This little shell is exactly like Bittium granarium, only that 

 it is a full grown shell and is most minute. The upper whorls 

 seem as if they were margined with a very dark brown line. 

 It is very remarkable that B. gra?iariu7n varies very nuich in 

 size, and though I never saw any so small as the present 

 species, still intermediate sizes may yet be found. The 

 ordinary size of that shell is over an inch in length. 



