Costa Rica Miocene — Olsson 



17 



with that characterizing the Chesapeake Miocene fauna of the 

 eastern United States and shows their close agreement in age. 

 The recent species and their closely related forms in the Gatun 

 fauna are as follows: 



Area occidentalis Phil. West Indian 

 Area umbonata Lamarck West Indian 

 Area eandida Gmelin West Indian 

 Area aurieulata Lamarck West Indian 

 Ostrea megodon Hanley Pacific 

 Anomia simplex d'Orb. West Indian 

 Phaeoides radians Conrad var. medioanierieanus 



Olsson West Indian 

 Phaeoides trisuleaiiis Conrad West Indian 

 Glyeymeris eastaneiis Lamarck West Indian 

 Glyeymeris deeussatus Linne West Indian 

 Divarieella qiiadrisuleata d'Orb. West Indian 

 Cardium 7?iedium Linne West Indian 

 Cardium spinosum var. Turtoni Dall East Atlantic 

 Cardium serratum Linne West Indian 

 Pitaria eireinata Born and its var. alternata Broderip 



West Indian and Pacific 



Antigona multieostata Sowerby Pacific 



Antigona rugosa Gmelin West Indian and Pacific 



Macroeallista inaeulata Linne West Indian 



Chio7ie grus Holmes West Indian 



Tellina erystallina Chem. West Indian and Pacific 



Strigilla pisiformis Linne West Indian 



Maetra exoleta Gray Pacific 



Mactra alata Spengler West Indian 



Labiosa lineata Say West Indian 



Corbula Dietziana C. B. Adams West Indian 



Tellidora eristata Recluz West Indian 



Conus proteus Hwass West Indian 



Conus floridanus Gabb var. eostarieensis Olsson West Indian 

 Terebra benthalis Dall var. boeasensis Olsson West Indian 



