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1049 



TERTIARY FAUNA OF FLORIDA 



Macoma alumensis n. sp. 

 PLATE 47, FIGURE 8. 



Miocene of Alum Bluff, Calhoun County, Florida; Burns. 



Shell solid, inequivalve, inequilateral; beaks inconspicuous, pointed; left 

 valve more convex and flexuous, right valve flatter and less flexuous ; anterior 

 end longer, the dorsal margin nearly parallel with the base in the left valve, 

 the end evenly rounded into the base, which towards the posterior end is a 

 little sinuated ; posterior dorsal margin rapidly descending ; a keel near it 

 rises above the line of the margin to the strongly flexed point, which is near 

 the base ; surface smooth except for incremental lines ; right also with a 

 strong keel, so that the margins of the valves meet at the bottom of a deep 

 sulcus behind the beaks when closed ; hinge-teeth normal ; hinge-plate solid 

 and heavy, especially in the right valve ; pallial sinus discrepant in the two 

 valves, but in both low, rather short, rounded behind, and about half confluent 

 with the pallial line below. Lon. 20, alt. 12, diam. 8 mm. 



Macoma Lyelli Dall. 

 PLATE 37, FIGURES g, 10, n. 

 Macoma Lyelli Dal!, Am. Journ. Sci., x'viii., p. 298, Oct., 1894. 



Miocene (and Pliocene?) of Gay Head, Martha's Vineyard, Massachusetts; 

 Dall and Woodworth. 



This is the shell alluded to by Sir Charles Lyell in his account of his visit to 

 Gay Head as " a Tellina resembling T. biplicata." It is closely related to Ma- 

 coma obliqua ]. Sowerby, of the English Crag, but is less produced in front 

 and more excavated on the posterior dorsal margin. It occurs only in the form 

 of very perfect internal casts in the Miocene clay of Gay Head, where it is 

 the most abundant molluscan fossil. In the sands unconformably superposed 

 on the clays fragments supposed to belong to this species were collected which 

 may perhaps be Pliocene. 



Macoma tenta Say. 

 fPsammobia lusoria Say, Journ. Acad. Nat. Sci. Phila., ii., p. 304, 1822; not of Conrad, 



1840. 



Tellina tcnta Say, Am. Conch., plate 65, fig. 3, 1834. 

 Macoma tenta Dall, Bull. 37, U. S. Nat. Mus., p. 60, pi. 56, fig. 10, 1889. 

 Tellina Souleyetiana Recluz, Journ. de Conchyl., iii., p. 253, pi. 10, fig. 5, 5', 1852 ; not 



T. Souleyeti Hanley, 1844, P- Z. S., p. 71. 

 Tellina (Peronaa) Recluziana Tryon, Cat. Tell., p. 98, 1869. 



