518 



GEOGRAPHICAL ZOOLOGY. 



[PART iv. 



Oncidium (16 sp.), South Europe (1 sp. British), Mauritius, 

 Australia, and Pacific Islands; Vaginulus (20 sp.), Neotropical 

 and Oriental regions. 



FAMILY 25. LIMMSID^E. (7 Genera, 332;Species.) 



GENERAL DISTRIBUTION. 



The Limnseidse, or Fresh-water Snails, inhabit ponds and 

 rivers in most parts of the world, but appear to be absent from 

 the Australian region. The genera are distributed as follows : 



Limncea (95 sp.), Nearctic, Palaearctic, and Oriental regions ; 

 Ckoanomphalos (2 sp.), Lake Baikal ; Pompholyx (2 sp.), Western 

 America; Chilinia (18 sp.), South America; Physa (20 sp.), 

 Nearctic, Palaearc tic, Ethiopian, and Oriental regions, and extends 

 to above 73 North Latitude in Siberia, being the most Arctic of 

 land or fresh- water shells; Ancylus (49 sp.), Nearctic and 

 Neotropical regions, Europe, and New Zealand; Planorbis (145 

 sp.), Nearctic, Palaearctic, and Oriental regions. Several genera 

 are found fossil, chiefly in the Wealden, Eocene, and Miocene 

 formations. 



FAMILY 26. AUKICULID^. (I Genera, 21Q Species.) 



GENERAL DISTRIBUTION. 



The Auriculidse are chiefly found near the sea in hot countries 

 and are most abundant in the Eastern tropics. They are absent 



