TRANSACTIONS OF WAGNER 

 I IOO 



TERTIARY FAUNA OF FLORIDA 



from Yucatan and the others from the Pliocene of Florida. The two speci- 

 mens with twenty-nine and thirty ribs came from Florida and Vera Cruz, 

 Mexico, but a valve from Cape May, New Jersey, had twenty-eight ribs, and 

 so did one from the Pliocene of the Caloosahatchie. Thirty-one of the forty- 

 five specimens had between twenty-three and twenty-six ribs. The species is 

 very uniform in its general character, becoming more oblique and elongated 

 with age, and having the two forms common to all species of Cardium, one 

 more elongated and oblique, and one more quadrate and equilateral. 



There is no living member of Dinocardium on the Pacific coast, but C. 

 Mcekianum Gabb, 1869, from the Pliocene of California is related to C. ro- 

 bustum. 



Roemer described a Cardium elcgantulum in 1849 from the American 

 Cretaceous, but as this was transferred to the genus Liopistha before its con- 

 flict with C. elcgantulum Beck, 1842, was noticed, there will be no occasion for 

 any change now. 



There is a Cardium multisulcatum from the South American Tertiary de- 

 scribed from Darwin's collections in 1846, but this name had previously been 

 used by Sowerby (P. Z. S., 1833) an( J the former species (cf. Philippi, Tert 

 Verst. Chile, p. 178, 1887) may take the name of C. Darwini. 



Subgenus FRAGUM Bolten. 



Section Fragiim s. s. 

 Cardium (Fragum) gatunense n. sp. 



Black Eocene shales of Gatun, Isthmus of Darien ; R. T. Hill. 



Shell solid, high, truncate behind, rounded in front, nearly equilateral, 

 radiately ribbed with flattened ribs separated by narrower channelled inter- 

 spaces ; there are sixteen ribs in front of the truncation, which is bordered 

 by a single rib more prominent than the others, behind which are about ten 

 others ; the truncation is bordered by an obtuse margin and the edges of the 

 ribs in the channels are, as it were, fringed by small imbrications ; on the body 

 and posterior truncation the ribs are dotted sparsely with small globular tu- 

 bercles, generally worn off; in front of the somewhat anteriorly gyrate um- 

 bones and also behind them near the margin are spaces where the ribbing is 

 obsolete, but not defined as lunule or escutcheon by any boundary ; the margins 

 are serrate or squarely notched, and the internal flutings run well up on the 

 disk ; the hinge and scars are normal. Lon. 23, alt. 28, diam. circa 23 mm. 



