LIST OF CYCLOPHORID2E. 



Fam. I. CYCLOPHORID^E. 



Mollusca phaneropneuinona Gray, Lond. Med. Rep. 1821. 



M. pneumonopoma Latr. 



Cyclostomina M. Edwards. 



Cyclostomoidea Fitzinger, Syst. Verz. 115. 1833. 



Cyclostoniaceen Pfeiffer, Menke und Pfeiffer, Zeitsch. fur Malah. 



1847, 101. 

 Cyclophoridse Gray, Proc. Zool. Soc. 1847, 181. 

 CyclostomidEe Gray, Turton. Man. ed. 2. 102. 273. (1840). 

 Cyclostomidse (pars) UOrb. Moll. Canar. 1837?, Moll. Cuba, i. 



199. 236. 1841 

 Cyelostomacea Menke, Syn. ed. 2. 39. 1830; Pfeiffer, Symb. Hist. 



Helic. i. 4. 1841, in Chemn. Conch, ed. 2. i. 19. 7. 1846. 

 Cyelostomacea (pars) Anton. Verz. xiii. 52. 1839 ; Reeve, Conch, 



Syst. ii. 90. 

 Cyclostomiatas Menke, Syst 22. 1828. 

 Turbinina Ferussac, Prod. 

 Turbinacea (pars) Rafin. Annal. JSat. 144. 1815. 



A. Operculum orbicular often concave externally, of many very 

 gradually enlarging whorls, nucleus central. 



a. Operculum thick, formed of two lamina, with a groove on the 

 edge between them ; the outer layer calcareous, usually fur- 

 nished with a raised border on the outer edge, forming a spiral 

 ridge or fringe. 



1. CYCLOTUS. 



Operculum thick, testaceous ; outer surface rather concave ; whorls 

 numerous, very gradually enlarging, fringed. — Shell subturbi- 

 nate, depressed or discoidal. Mouth simple, or with a reflexed 

 outer lip. Peristome continued, or joined by a callous margin ; 

 straight or reflexed. 



A 3 



