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793 



TERTIARY FAUNA OF FLORIDA 



Modiolus silicatus n. s. 

 PLATE 27, FIGURE 28. 



Upper Oligocene of the silex beds at Ballast Point, Tampa Bay, Florida ; 

 Willcox and Dall. 



Shell small, smooth, short, broad, moderately convex, with a few incre- 

 mental strias ; beaks low, anterior end very short, posterior margin elevated, 

 rounded, anterior margin slightly impressed; basal end rounded; inner 

 margin smooth, with an unusually deep ligamental sulcus. Alt. 22, max. 

 lat. 1 6, diam. 9 mm. 



This is somewhat like the Miocene M. inflatits T. and H., but a much 

 smaller shell, with a less impressed lateral area and less sinuous anterior 

 margin. 



Modiolus inflatus Tuomey and Holmes. 



Mytilus inflatus T. and H., Pleioc. Fos. S. Car., p. 33, pi. 14, fig. 3, 1855. 

 /', rna inflatn Conrad, Proc. Acad. Nat. Sci. for 1862, p. 579, 1863. 

 Mt'iUola inflala Whitfield, Mioc. Moll. N. J., p. 39, pi. 6, figs. 3, 4, 1895 (not Modiola 



injlatti Whitf., Lam. Rar. Clays, p. 197, pi. 26, figs. I, 2, 1885). 



Lower Miocene of Shiloh and Bridgeton, Cumberland County, New 

 Jersey, Burns ; Miocene of South Carolina at Giles Bluff, Peedee River, 

 Tuomey. 



This species is closely related to the recent M. tiilipus Lam. 



Modiolus Ducatelii Conrad. 

 Mi>iii(>/ii tlucatelii Conrad, Medial Tert., p. 53, pi. 28, fig. 2, 1840. 



Miocene of Calvert Cliffs, Maryland, Professor Ducatel; of Jericho, New 

 Jersey, Burns ; of York River, Virginia, Harris ; of the Natural Well, 

 Duplin- County, North Carolina, Burns. 



This large species is rather abundant in the Maryland Miocene, but 

 rarely perfect. The M. gigas Wagner (Trans. Wagner Inst, iv., p. IO, pi. 2, 

 fi^r. 2, a-b, 1897) differs by its much wider posterior part and attenuated 

 anterior end. It is also Miocene. 



The other valid species, belonging to the section Modiolus as restricted, 

 found in our Tertiary except M. inlifns Lam., which occurs in the later rocks 

 of the West Indies, arc all California!! and include M. capax Conrad, Pliocene 

 and. Pleistocene (as well as recent); M. flabcllatits Old., Pliocene and recent; 

 M. n-cins Conrad, Miocene and recent ; while the M. modiolns L., which is 

 said to go back to the Miocene (?) in California, is known from Pleistocene 

 deposits on both sides of the continent as well as the shores of Kurope. 



