397 



Costa Rica Miocene — Olsson 



225 



of left valve 4,50 mm. The D. prevaricata Guppy of the Mio- 

 cene of Santo Domingo and Jamaica measures only 8 mm in 

 height. 



The D. quadri sulcata is a recent species of the West Indies 

 appearing in the east coast Miocene of the United States for the 

 first time in the Upper Chesapeake. 



Gatun Stage: Coll. 4, 5, Red Cliff creek. 

 Middle creek. 



Genus CARDIUIVI, Linne 

 Subgenus TRACHYCARDlUiVl, Moerch 



Cardium Stirsatum Brown and Pilsbry Plate 27, figures 4, 5 



Cardiuni {Trachy cardium) stiriatum Brown and Pilsbry, 191 1, Proc. 

 Acad. Nat. Sci. Phila., vol. 63, p. 366, pi. 28, fig. 11. 



This is most elegant of the several species of Cardium in 

 the Miocene of Panama and Costa Rica. The shell is high and 

 inflated with about 30 radial ribs which are peculiarly sculptur- 

 ed with twisted or obliquely projecting tuberclers placed on the 

 posterior side of the ribs and overhanging the adjacent inter- 

 space. Large specimens may reach a height 50 mm. It is re- 

 lated to the recent West Coast Cardium belcheri Broderip. 



Gatun Stage: Gatun, C. Z. 



Water Cay ^ Panama. 

 Hill No. I, Ba?ia?ia River. 



Cardium dominicense Gabb Plate 27, figure 2 



Cardium )Trachycardiimt) dominicense Gabb, 1873, Trans. Amer. 

 Phil. Soc., vol. 15, p. 25. 



Cardium {Tr achy cardium) dominicense Qsihh, 1881, Journ. Acad. Nat. 

 Sci. Phila. , 2nd series, vol. 8, p. 344. 



Cardium {Trachycardium) gatunensis Toula, 1908, Jahrb. der K-K 

 Geol. Reichsanstalt Wien. vol. 58, p. 720, pi. 27, fig. 4. Not Card- 

 ium {Fragum) gatunensis Dall, 1900, 



