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TERTIARY FAUNA OF FLORIDA 



Cardium Emmonsi Conrad, Am. Journ. Conch., in., p. 13, 1867. 



Cardium floridanum Heilprin, Trans. Wagner Inst., vol. i., pp. 92, 103, pi. xi., fig. 25, 

 1887. 



Pliocene marls of the Caloosahatchie and Shell Creek, Florida, Willcox ; of 

 North Carolina, at Walker's Bluff, Cape Fear River, Emmons. 



This form has nine ribs on the posterior with hood-like imbrications ; ten 

 on the disk with high, arching imbrications continuous on the posterior side ; 

 and ten anterior, with cup-like ornaments like strung convolvulus flowers. The 

 nearest recent relative is C. consors Broderip, of the Pacific coast. It is rather 

 rare in the marls. 



Cardium (Trachycardium) isocardia Conrad. 



<C Cardium isocardia Linne, Syst. Nat., ed. x., p. 679, 1758; ed. xii., p. 1122, 1767; Dill- 



wyn, i., p. 118. 

 Cardium isocardia Chemnitz, Conch. Cab., vi., p. 182, pi. 17, figs. 174-176, 1782; Reeve, 



Conch. Icon., ii., Cardium, pi. 17, fig. 84, 1845. 



Cardium Egmontianum Shuttleworth, Journ. de Conchyl., v., p. 472, 1856. 

 f Cardium eburniferum Guppy, Ann. Mag. N. Hist., 4th Ser., xv., p. 51, pi. vii., fig. 3, 



1875. 



Miocene of North Carolina at Wilmington ; Pliocene of the Caloosahatchie 

 and Myakka Rivers, Florida; Pleistocene of North Creek, Osprey, Florida; 

 recent from off-shore near Cape Hatteras, North Carolina, southward through 

 the West Indies to Trinidad. 



This is the type of the subgenus, and has about twenty-seven to thirty-three 

 ribs, with comparatively low and distant arcuate imbricating scales ; the ribs 

 are squarish and the interspaces channelled, the scales tend to be seated on 

 the posterior side of the ribs ; on the anterior face of the shell the imbrications 

 are closer, lower, and heavier, but these ornaments change their form very 

 gradually from one end of the shell to the other. 



Linne and the earlier writers confounded this shell with a similar form 

 from the East Indies which was afterwards named C. squamosum by Gmelin. 

 A specimen of the West Indian shell was in the Linnean cabinet and serves 

 to hold the name, though among the figures cited by him several referred to 

 the Oriental shell. Guppy has described a shell from the Gulf of Paria which 

 appears to be this species, though with rather more ribs than usual, but I 

 know it only from his figure. 



The spines are sometimes more distant and are then usually longer than 

 common. 



