508 GEOGRAPHICAL ZOOLOGY. [PART iv. 



FAMILY 4 CONID^E. (3 Genera, 850 Species.) 



DISTRIBUTION. The Cones are universally distributed, but 

 this applies only to the genus Pleurotoma. Conus is tropical 

 and sub-tropical, and Cithara is confined to the Philippine 

 Islands. There are about 460 fossil species, from the Chalk 

 formation to the most recent deposits. 



FAMILY 5. VOLUTID^E (5 Genera, 670 Species.) 



DISTRIBUTION. The Volutes are mostly tropical ; but a small 

 species of Mitra is found at Greenland, and a Marginella in the 

 Mediterranean. Cymla is confined to the West Coast of Africa 

 and Portugal. Valuta extends south to Cape Horn. There are 

 about 200 fossil species, from the Chalk and Eocene to recent 

 formations. 



FAMILY 6. CYPE^ID^E. (3 Genera, 200 Species.) 



DISTRIBUTION. The well-known Cowries are found all over 

 the world, but they are much more abundant in warm regions. 

 One small species extends to Greenland. There are nearly 100 

 fossil species, from the Chalk to the Miocene and recent forma- 

 tions. 



FAMILY 7. NATICID^E. (5 Genera, 270 species.) 



DISTRIBUTION. The Naticidse, or Sea-snails, though most 

 abundant in the Tropics, are found also in temperate seas, and 

 far into the Arctic regions. Two other genera are fossil ; and 

 there are about 300 extinct species, ranging from the Devonian 

 to the Pliocene formations. 



