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I IOI 



TERTIARY FAUNA OF FLORIDA 



This well-marked species is abundant in the shales, but the matrix is so 

 much tougher than the remains of the shell that the characters have to be 

 determined from a large number of imperfect specimens. 



Cardium (Fragum) sp. indet. 



Oligocene marl of Bowden, Jamaica ; Henderson and Simpson. 



A fragment of a Cardinal resembling C. medium was obtained from the 

 marl but is too imperfect for description and is noted here to avoid the omis- 

 sion of this element in the Bowden fauna. It may be the same as the follow- 

 ing species, but is very much larger than any of the Chipola specimens. 



Cardium (Fragum) Burnsii n. sp. 

 PLATE 48, FIGURE 15. 



Oligocene of the Chipola River, Calhoun County, Florida ; Burns. 



Shell small, subquadrate, moderately inflated, truncate behind, rounded in 

 front, with rather low beaks ; sculpture of on the body twenty-two to twenty- 

 four subequal rounded ribs with narrower channelled interspaces, sharply 

 cross-striated between the ribs ; on the posterior truncation twelve to fourteen 

 similar but smaller ribs, a few near the hinge-margin wider than the rest, 

 with no marked smooth area between them and the margin either in front 

 of or behind the umbones; an easily detachable outer layer covers the ribs 

 with fine concentric threading, rising at intervals into semilunar small nodules, 

 all of which is frequently worn off when the ribs appear polished ; internally, 

 the margin is strongly fluted ; hinge normal, strong. Lon. 6.5, alt. 7.0, diam. 

 6.0 mm. A single broken valve reaches 10 mm. in height. 



This little shell stands almost midway between typical Fragum and Tri- 

 goniocardia, having the striated interspaces of the latter and the numerous 

 similar subequal ribs of the former. It seems abundant in the marls. 



Cardium (Fragum) medium Linn. 

 Cardium medium Linne, Syst. Nat., ed. x., p. 678, 1758; ed. xii., p. 1122, 1768; Reeve, 



Conch. Icon., ii.. Cardium, pi. vi., fig. 30, 1844; Roemer, Conch. Cab. Neue Ausg., 



p. 102, pi. iv., figs. 5-7, 1869. 



Cardium venustum Dunker, Mai. Blatt., viii., p. 37, 1861. 

 Hemicardium columba Heilprin, Trans. Wagner Inst., i., p. 93. P 1 - xi -. % 26 ' l886 - 



Miocene of St. Mary's River, Maryland, W. B. Clark; of the Natural 

 Well, Duplin County, North Carolina ; Pliocene of the Caloosahatchie River, 



