TRANSACTIONS OF WAGNER 

 688 



TERTIARY FAUNA OF FLORIDA 



0. pandcEformis Gabb, 1862, an unfigured, supposedly Cretaceous, species, 

 is regarded as unidentifiable by Dr. C. A. White, but is considered by Aldrich 

 to be Jacksonian and identical with 0. Tjiomeyi Conrad. It is, perhaps, from 

 Aldrich's remarks, a form of trigonalis. 



GryphcEa athyroidca Guppy (1866), from the Tertiary of Trinidad, appears 

 to be a true Ostrea and distinct from any of the continental species. 



I have not attempted to make comparisons with the European species, 

 as that would require a series of the latter, which is not accessible, but a 

 casual inspection of the figures does not give the impression that there are 

 many of them which might be identical with American forms. 



Superfamily NAIADACEA. 



Family UNIONIDvE. 



Genus UNIO Retzius. 



TJnio (Unio) caloosaensis n. s. 



Plate 25, Ficures 6, 12 «. 



Pliocene marls of the Caloosahatchie River, Florida; Dall. 



Shell oblong-ovate, rounded in front, somewhat pointed at the ventral 

 angle behind, umbonal region only moderately prominent, sculptured with 

 numerous fine concentric wrinkles and seven or eight wavy, sharpl}^ elevated, 

 narrow, concentric ripples ; the latter are most prominent on the line of the 

 posterior angle of the valves, on each side of which the ripple recedes, per- 

 ceptibly making a small sinus, more conspicuous than any of the small fluctua- 

 tions of the rest of the ripple; sides moderately compressed; ventral margin 

 gently arcuate, straight, or slightly incurved just in front of the posterior angle 

 which forms the ventral boundary of the posterior dorsal area ; posterior end 

 rounded above, slightly rostrate ventrally ; valves solid, nearly smooth, or with 

 more or less irregular incremental sculpture and faint traces in some specimens 

 of obscure radial lines near the posterior ventral angle ; interior with strongly 

 impressed pallial line and muscular impressions ; " cardinal" teeth short, the 

 ventral one usually stouter in the right and the dorsal in the left valve ; laterals 

 low, solid. Lon. 57, diam. 20, alt. 32 mm. 



This species, though usually defective, is not uncommon in the marls and 

 sometimes with the valves in their natural position. The species belongs to 

 the group of Unio Biickleyi of the recent fauna, which is abundantly represented 

 in the Floridian lakes. Having submitted it to Mr. Charles T. Simpson, who 



