rir.\r. xxii.] MOLU'SCA. 507 



Class.— GASTEROrODA. 



Order T.—PBOSOBRAXCHIA TA. 



Family 1.— STROMBID.K. (4 Genera, 8(3 Species.) 



Distribution.— The Stronil)i(Ia\ or Wing-sliells, iiihaliit tropi- 

 cal and \^'arm seas from the ^Mediterranean to Xew Zealand ; most 

 abundant in the Indian and Pacitic Oceans. There are nearly 

 200 fossil species, from the Lias to 5iIiocene and recent deposits. 



Family 2.— :\irincn).F. (12 Genera, 1000 Species.) 



Distribution. — All sens, most abundant in the Tropics. 

 Ti'icJwti'opis is confined to Northern seas ; Mnrcx and Fksvs are 

 cosmopolitan. There are aliout 700 fossil species, ranging from 

 the Oolite to the I\liocene and recent formations. 



Family 3.— r.UCCIXIl )A-:. (24 Genera, 1 100 Species.) 



Distribution. — The I'uccinidcC, or " "Whelks," range over the 

 whole world, but some of the genera are restricted. B\iccinvm 

 inhabits the north and soutli temperate seas ; Monoccros the 

 West Coast of America ; Cassidaria the jMediterranean ; Phos, 

 Haiyo, Ehurna, and Bicinvia, are confined to the Pacific ; BJoI- 

 inm inliabits the Mediterranean as well as the Pacific, There 

 are about 350 fossil species, mostly from the Eocene and Miocene 

 beds. 



