114 MOLLUSCA. 



No. 285. Turritella Mortoni, Con. 



Claiborne Epoch (Eocene), Monroe Co., Alabama. 



No. 286. Turritella terebra, Linn. 

 (Turritella triplicata, Born.) 

 Quaternary, Palermo, Sicily. 



No. 287. Cyclonema bilix, Con. 



Forty species are known of this genus, from the Palaeozoic. Family Lit- 

 toridse. Cincinnati Group (Lower Silurian), Waynesville, Ohio. 



No. 288. [618, Cast]. Cerithiura giganteum, Lam. 



This genus, which abounded in Geological periods from the 

 Trias to the present time, was distributed widely then as now in 

 the seas over all parts of the globe. It had its culmination in 

 numbers, as well as in size of individuals and variety of forms, 

 during the Tertiary period. 460 fossil species are known. Fam- 

 ily Cerithiidae. This magnificent specimen — the largest of all 

 fossil gasteropods — is from the Eocene Tertiary at Damery, 

 France. Size, 22 x 7. 



No. 289. Cerithium Bronni, Partsch. 

 Miocene, Steinabrunn, Austria, 



No. 290. Ampullaria vulcani, Br. 



This is the type genus of a family of fresh water 

 mollusks, which are widely distributed in the tropics. 

 The Paludinidae represent them in temperate latitudes. 

 Eocene, Ronco, Italy. 



No. 29L Pyrgulifera humerosa, Meek. 

 Upper Cretaceous, Sulphur Creek, Wyoming. 



No. 292. Turbo rugosus, Linn. 



This genus begins in the Silurian, and still exists. 400 fossil species are 

 known. Family Turbinidae. Quaternary, Ficarizzi, near Palermo, Sicily. 



No. 293. Trochus podolicus, Dubois. 



This genus has a pyramidal shell with a flat base; 360 fossil species are 

 known since the Silurian ; 250 species living. Family Trochidse. Miocene, 

 Vienna, Austria. 



No. 294. Trochus magus, Linn. 

 Quaternary, Palermo, Sicily. 



