BY E. M. JOHNSTON, F.L.S. 



83 



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Genus Hipponyx. Defrance. (185-187.) 

 Shell thick, obliquely conical, non-spiral ; apex somewhat 

 posterior and curved backwards ; muscular impression, 

 horse-shoe shaped ; base of attachment shelly. Dist. — • 

 Almost world-wide. 



Sub-Genus Amalthea. Schum. 

 lake Hipponyx, but without shelly base ; impression crescent- 

 shaped. This form is usually found attached to living 

 shells. 



(xxv.) Family Solaeiid^i. 



(Shell orbicular, depressed, or trochiform ; aperture generally 

 angular ; umbilicus usually wide and deep ; oper- 

 culum corneous, spiral.) 



Genus Solarium. Lam. (188-189.) 

 Shell depressed, conical, angular at periphery ; aperture, sub- 

 quadrangular, lip simple ; umbilicus wide, . spiral, its 

 margins crenulated ; operculum horny, sub-spiral. 

 Dist. — Tropical, world-wide. 



Genus Adeoebis. S. Wood. (190.) 

 Shell depressed, orbicular, widely umbilicated; whorls not 

 numerous, smooth or striate, the last somewhat 

 angular ; aperture rounded, the outer lip arcuate, simple, 

 sharp ; operculum shelly, sub-spiral. Dist. — West 

 Indies, China, Australasia. 



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(xxvi.) Family ScALAEiDiE. 

 Genus Scalaeia. Lam. (191-202.) 

 a hell mostly white and lustrous; turrcted ; many whorled ; 

 whorls round, sometimes separate, ornamented with 

 numerous transverse ribs ; aperture round ; peristome 

 continuous ; operculum horny, few whorled. Dist. — ■ 

 Mostly tropical. 



Sub-Genus Ceossea. A. Adams. 

 Shell turbinate, umbilioited, white ; whorls convex, cancellated, 

 simple or with varices; aperture roundish, anteriorly 

 angular, somewhat produced and canaliculate ; 

 umbilicus surrounded and narrowed by a callus. 

 Occurs also fossil in Australia and Tasmania, in rocks 

 of Eocene age. 



