TRANSACTIONS OF WAGNER 

 1094 



TERTIARY FAUNA OF FLORIDA 



Shell small, solid, plump, slightly oblique and inequilateral, suborbicular, 

 with moderately prominent beaks ; sculptured with twenty-one strong, rounded 

 ribs (of which six are smaller and on the posterior area) separated by nar- 

 rower, sharply channelled interspaces ; concentric sculpture irregular but rather 

 marked, cross-striating the channels and forming thickened loops over the 

 backs of the ribs ; surface polished, a small, smooth, pseudo-lunule in front 

 of the beaks, hinge normal, strong for the size of the shell, the internal margins 

 deeply channelled, the sulci reaching well up on the disk. Alt. 11, Ion. 11, 

 diam. 9 mm. 



It is possible that this species should be placed next to C. ctenolium among 

 the typical Cardia, but the sculpture is more like that of Cerastoderma. 



CardiurQ (Cerastoderma) druidicum n. sp. 



Plate 40, Figure 7. 



Oligocene of the Oak Grove sands, Santa Rosa County, Florida ; Burns. 



Shell small, rather thin, with moderately high beaks ; produced and pointed 

 behind, rounded below and in front; sculptured with about sixteen strong, 

 rounded ribs with narrower channelled interspaces ; on the posterior area are 

 five flattened, smooth ribs separated by narrow sulci ; the anterior ribs, espe- 

 cially towards the margin, show low transverse ridges rather regularly and 

 distantly arranged, as in Dinocardium, the anterior four or five ribs, however, 

 are smaller and smooth; transverse sculpture, except that just mentioned, 

 only of incremental lines; a small, smooth pseudolunule ; hinge small, deli- 

 cate, normal ; anterior and basal margins fluted, the sulci ascending as high 

 as the lower edges of the adductor scars. Lon. 25, alt. 22.5, diam. 15 mm. 



This is an elegant little shell foreshadowing the characters of Dinocardium, 

 but also related intimately to Cerastoderma. 



Cardium (Cerastoderma) virg-inianum Conrad. 

 Cardium virginianum Conrad, Fos. Medial Tert., Cover of No. i, and p. 33 (No. 2), pi. 



18, fig. I, April, 1839; not Protocardia virginiana Conrad, 1864. 

 Cardium ingens Conrad, as of Wagner, op. cit., p. 33, 1840; not of Wagner (MS. 1839). 



Trans. Wagner Inst., v., p. 10, pi. 3, fig. 2, 1897. 

 Cardium quadrans Rogers, Trans. Am. Phil. Soc., 2d Ser., vol. v., p. 375, pi. xxx., fig. i, 



Dec, 1839. 



Miocene of Virginia at Suffolk and Grove Wharf ; of Alum BlufT, Florida ; 

 and of Gay Head, Martha's Vineyard, Massachusetts. 



