- 1-98 - 



is especially tliin, and therefore subtranslucent, obseiure 

 radial narki.-igs are visible external Ij'. 



OcGiirreiicc .- Up-oer Oligocene: Ohipola iiiarl, j'lorida (Dall, 

 19 >^) I LoK'er l.rioc ene ; Bowden beds, 3owden, Jamaica 



(Dall, 1900). 



