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799 



TERTIARY FAUNA OF FLORIDA 



Adula H. and A. Adams, 1857. Shell rhombic, with subcentral beaks; sur- 

 face polished, clean. Type L. soleniforinis Orbigny. 



Leiosolcnns Carpenter, 1856. Shell like IMhophaga, but building a doubly 

 tubular spout to the aperture of its burrow, and therefore probably 

 furnished with elongated tubular siphons. Type L. spatiosus Cpr. 



Myoforccps Fischer, 1886. Shell as in Lillwphaga, but the animal has the habit 

 of depositing a calcareous crust on the exterior of the valves, which covers 

 them smoothly and projects in a twisted process from the posterior end 

 of each valve. Type L. caudigcra Lamarck. 



Dilicrus Ball, 1898. Resembling Alyoforccps, but with two or more radial sulci 

 extending backward from the beaks, with the incrustation plume like, 

 arranged in a distinct pattern on the areas between the sulci, and, when 

 projecting beyond the ends of the valves, apposited symmetrically, not 

 alternate and twisted as in the last section. Type L. pluimila Hanley. 



The genus is commonly represented in the Tertiary rocks by casts of its 

 burrows, but the shells are so thin and fragile as to be rarely preserved. Most 

 of those here mentioned are silicious pseudomorphs which preserve the form 

 and markings of the original shell. 



Lithophaga antillarum Orbigny. 

 I.illii>,/niin/s iinlillaniin Orb., Moll. Cubana, ii., p. 332, pi. 28, figs. 12, 13, 1847 (Spanish 



edition and atlas, 1845). 



M,<,iioln i-omttfata Phil., Abbilcl. und Bcschr., ii., 147, pi. I, fig. i, 1846. 

 Li//K><t<>/in<* it'rrit^titi/s Reeve, Conch. Icon., x., pi. I, fig. I, 1858. 

 I.ithtifiliti^iix ilactyliis Miirch, Cat. Yoldi, ii., p. 55, 1853 ; not of Sowerby, 1824. 

 Lii/i,<f>/iiii,'n.<i caribous Dal], Bull. U. S. Nat. Mus., No. 37, p. 38, No. 81, 1889; not of 

 Philippi. 



Oligocene silex beds at Ballast Point, Tampa Bay, Florida, Willcox and 

 Dall ; recent from Florida southward through the Antilles. 



The reason why this species has not turned up in later formations is 

 probably the extreme fragility of the shell and the less favorable opportunities 

 for preservation. It would naturally have been absent through the colder 

 period of the Miocene. It is among the St. Domingo fossils collected by 



Gabb. 



Lithophaga nigra Orbigny. 



i'xt-r Oil)., Moll. Cubana, ii., p. 331, pi. 28, figs. 10, II, 1847 (Spanish 

 edition and atlas, 1845). 



