199 Costa Rico Miocknk — Olsson 27 



The Area Henekeni, Glycymeris jamaicensis and Protocardia 

 gurabica occur with a typical Gatun fauna at Water Caj^, west- 

 ern Panama, associated with Sconsia, and other Gurabo shells. 

 With the exception oi Ringicula dominicana ,\)s\^ other species are 

 generally rare. The evidence is therfore strongl}^ in favor of 

 the equivalence of the Gatun beds with the Gurabo of Santo 

 Domingo. 



Bowdp:n Beds, Jamaica 



Next to Santo Domingo, the highl}^ fossiliferous beds at 

 Bowden, Jamaica, are the best known. From this locality, Dall 

 has listed about 435 species, of which 12 per cent, appear to be 

 identical with recent species. 



Recent correlation b}^ Cooke places the Bowden beds as 

 equivalent to the Gurabo formation of Santo Domingo, and there- 

 fore to the Gatun formation; a correlation which is borne out by 

 our own studies. About 38 Gatun species, not including recent 

 forms, are here considered equivalent to Bowden shells. In gen- 

 eral, the Costa Rican localities which show the closest agree- 

 ment with Bowden, are the upper coralline horizons, so that the 

 Bowden beds may be a little higher than the main Gurabo and 

 they are so considered here. The following Bowden shells oc- 

 cur in the Costa Rican Gatun. 

 "^Adeocina bullata Kiener 



''Acteocina recta d'Orb Petaloconchus sculpturatus Lea 



^Volvulacylindrica Gabb A lata turrita Guppy 



Bullaria paupercula Sowerby ^Crepidula plana Say 



Terebra bipartita Sowerby *Nrtica near canrena Linne 



Conus planiliratus Sowerby Glycymeris jamaicensis Dall 



Conus stenostomus Sowerby *Arca occidentalis Philippi 



Conus granozonatiis Guppy *Arca auriculata I^amarck 



Conus recog?titus Guppy *Ostera megodon Hanley 



Conus interstifictus Guppy Limcsa solida Dall 



Conus gracilissimus Guppy Placunanoinia lithobleta Dall 



"^Turris albida Perry Echinochama antiquata Dall 



'^'Recent 



