TRANSACTIONS OF WAGNER 



TERTIARY FAUNA OF FLORIDA 



Semele mutica n. sp. 

 Plate 43, Figures 2, 12, 16. 



Upper Oligocene of the Chipola River, at McClellan's farm, Calhoun 

 County, Florida; Burns. 



Shell small, compressed, thin, rather elongate, with small, low, pointed 

 beaks ; anterior end slightly longer, rounded ; posterior end shorter, obscurely 

 folded and subtruncate below ; sculptLire variable, as follows : 



Variety Stearnsii Dall ; with few obscure concentric waves stronger about 

 the middle of the disk ; there is no radial sculpture, and the umbones have a 

 slightly compressed appearance. (Fig. 16.) 



Variety mutica Dall ; with the waves numerous, compressed, elevated into 

 narrow, somewhat irregular lamellje, with wider interspaces over the whole, 

 sharper and more crowded near the posterior dorsal slope ; no radial sculpture. 

 (Fig. 12.) 



Variety scintiUata Dall; with sculptLire like either of the preceding, to 

 which is added radial threading visible first towards the ends of the shell, in 

 some specimens covering the whole disk with rounded radial threads with wider 

 interspaces ; in the specimens with the strongest sculpture the threads overrun 

 the ridges, and even become nodulous towards the ends of the shell at the 

 intersections. (Fig. 2.) 



All these forms show a pretty uniform, minute, concentric threading, close 

 and almost microscopic, most evident in the interspaces, but covering the whole 

 surface, though often worn from the more projecting portions, such as the 

 tops of the waves. Alt. 7.5, lat. 11.5, diam. 3.0 mm. 



The variations of this pretty little shell are much greater than in any of 

 the recent species I have seen, but it appears to be a precursor of such species 

 as the Miocene 5". bella Conrad and the Pliocene and recent 6". cancellata 

 Orbigny. 



Semele carinata Conrad. 



Plate 36, Figures 23, 26. 



Amphidesma carinata Conrad, Journ. Acad. Nat. Sci. Phila., vi., p. 229, pi. g, fig. 23, 1830; 



Fos. Medial Tert., p. 27, pi. 19. fig. 7, 1838. 

 Smodesmia carinata Tuomey and Holmes, Pleioc. Fos. S. Car., p. 93, pi. 23, fig. 2, 1856. 

 Abra Holmesii Conrad, in App. Kerr, Geol. Rep. N. Car., p. 19, pi. 3, fig. 8, 1875. 

 Abra carinata Conrad. Proc. Acad. Nat. Sci. Phila., xiv., p. 574, 1863. 



Uppermost Oligocene of Oak Grove, Santa Rosa County, and Shoal River, 

 Walton County, Florida (var. compacta) ; Miocene of St. Mary's County, 

 Maryland, of the Natural Well and Magnolia, Duplin County, North Caro- 



