arched or outer margin. 1. G. triumphans. Troehus Guild- 

 fordise, Gray. 

 2. G. heliophorus. T. imperialis, Quoy, t. 40. f. 1. 



12. Pachypoma. Oper. oblong, subquadrangular, very convex 

 externally. 1. P. insequalis. Troehus i., Martyn. Troehus 

 gibberulus, Chemn. 2. P. cadatus. Troehus c, Gmelin. 



13. Lithopoma. Oper. ovate, thick, thicker at the end, with a 

 broad thin margin on outer edge. 1. L. tuber. Troehus t., 

 Linn. 



14. Imperator, n. 115. Oper. thin, flat, rather thinner on edge. 



1. I. Solaris. 



15. Tubicanthus, Swains. Oper. ovate, with a slight tubercle 



over axis, and a single subcentral arched rib. 1. T. Cooki- 

 anus. Troehus C, Quoy, t. 40. f. 2. 



l(i. Bolma. Oper. ovate, suborbicular, convex, with a subcen- 

 tral tubercle over axis and a broad submarginal spiral rib. 

 1. B.rugosus. Troehus v., Linn.; Joannis,t. 108. f. 5; Chiaje,t.\07. 

 f. 1,5, t.43. f.6. 



c. Eutropiana. Month and oper. ovute. 



17- Eutropia, n. 116. 

 1. E. australis. Phasianella bulimoides, Quoy, t. 41. f. 1, 2. {Cuoier, 

 Anat. Moll. t. .) 



Fam. 2. Liotiadee. 



Operculum horny, with an external calcareous coat formed of 

 numerous separate pearl-like shelly particles placed in spiral lines. 



1. Liotia, n. 136. Shell variced ; lips thick. 1. L. granulosa. 



Delphinula g., Dunker. 2. L. Krausii. Solarium cancella- 

 tum, Kraus. 3. L. cancellata. Delph. c, Gray=D. Cobi- 

 ensis, Reeve. 



2. Lippistes, n. 248, part. Mow (/".=Cyclostrema, Leach. Shell 



subdiseoidal ; mouth round, lips scarcely reflexed. 1 . L. can- 

 cellata. Cyclostrema c, Leach. 2. L. evoluta. Delph. e., 

 Reeve. 



3. Adeorbis, n. 140. 1. A. subcarinatus. Troehus s., Montague. 



Fam. 3. Trochidce. 



Operculum horny, of many gradually enlarging whorls, not covered 

 with a calcareous coat. No frontal fringe between the tentacula. 



* Operculum circular, many-whorled. 



1. Pyramis, n. 117- 



1 . P. obeliscus. Troehus o., Quoy, t. 39. f. 3. 



2. Cardinalia, n. 119. 



1. C. elata. Troehus e., Quoy, t, 61. f. 22. 26. 



