FREE INSTITUTE OF SCIENCE 



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 striae; beaks low, anterior end very short, posterior margin elevated, 

 rounded, anterior margin slightl)' impressed ; basal end rounded ; inner 

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

 lat. 16, diam. 9 mm. 



This is somewhat like the Miocene M. inflatus 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. 

 Perna inflata Conrad, Proc. Acad. Nat. Sci. for 1862, p. 579, 1863. 



Modiola inflata Whitfield, Mioc. Moll. N. J., p. 39, pi. 6, figs. 3, 4, 1895 (not Modiola 

 inflata 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. 

 Modiola ducatelii CowctiA, 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. 10, pi. 2, 

 fig. 3, 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. tiilipus Lam., which occurs in the later rocks 

 of the West Indies, are all Californian and include M. capax Conrad, Pliocene 

 and Pleistocene (as well as recent) ; M. flabellatus Gld., Pliocene and recent ; 

 M. rectus Conrad, Miocene and recent; while the AT. modiolus 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 Europe. 



