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.— LIMN^ID^. (7 Genera, 332 Species.) 



The Limneeidse, 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, Palsearctic, and Oriental regions ; 

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

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

 Nearctic, Palaearctic, 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 ; PlanorUs (145 

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

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

 formations. 



Family 26.— AUPJCULID^. (3 Genera, 210 Species.) 



The Auriculidffi are chiefly found near the sea in hot countries 

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



