Costa Rico Miocenk — Olsson 



19 



cene time and have been noted by several v/riters. They 

 comprise the following species from Panama and Costa Rica, 

 listed together with the Pacific analogues: 



Panama or Costa Rica Pacific Analogue 



Area Patricia Sowerby Area granclis Sowerby 



Area [Noetia) MacDonalcli Dall Area reversa Sowerby 



Ostrea megodon Hanley 

 Maetra exoleta Gray 



Maetra estrellana Olsson ....Rlaetra {Harvella) elega?is So\NQrhy 



Semele laevis Sowerby var. 



eostariecnsis Olsson Semele laevis Sowerby 



Maeoma panamensis Dall variety 



eanalis Olsson... Blaeoina panamensis Dall 



Maeoma gatunensis Toula Maeoma elongata Hanle}^ 



Tellina erystallina Chemnitz also West Indian 



Antigona inultieostata Sowerby 



Antigofta rugosa Gmelin also West Indian 



Pitaria eireinata Born variety 



allernata Broderip 

 Cyelinella snbquadrata Hanley variety 



qiiitana Olfson Cyelinella suhquadrata Hanley 



Cyelinella beteyensis Olsson Cyelinella A^'royeri Phili-ppi 



Conns reeognitiLS Guppy Conns pyriformis Reeve 



Turrieula lavinoides Olsson Turricula lavina Dall 



Caneellaria islaeolonis Maury Caneellaria tesselata Sowerby 



Caneellaria toroensis Olsson Coneellaria tubereulosa Sowerby 



Caneellaria Plummeri Olsson Caneellaria biillata Sowerby 



Mitra Swainsoni Brod. variety 



limonensis Olsson Mitra Swainsoni Broderip 



Neverita nereidis Maury Neverita glauea Humbolt 



Northia northiae Gray variety 



niioeeniea Olsson Northia narthiae Gray 



Malea eamura Guppy Malea ringens Swainson 



Oliva testacea Lam. variety 



eostaricensis Olsson Oliva testaeea Lam 



With the closing of the Miocene straits, this Pacific element 

 gradually had to give way before the developrnxcnt of the West 

 Indian fauna, but it is still to be seen in such species as, Tellina 

 crystalli7ia Chem. Architectonica gramilata Lamarck, which 

 have a distribution along both coasts. Moreover the Pliocene 



