TRANSACTIONS OF WAGNER 

 604 



TERTIARY FAUNA OF FLORIDA 



think there are probably family differences between the most nearly related 

 recent species of the respective groups, but because some of the best paleon- 

 tologists regard Area and Citcullcea as having reached their present status 

 through very different lines of descent. Doubtless they converge in geologi- 

 cal time, but the Arcidce appear to be a relatively very modern group, taken 

 as a whole. 



The name Macrodontida used for this family on pages 516-17 must be 

 dropped, since the generic name Macrodon is preoccupied, and Parallclodon 

 Meek proposed for the species which the former included ; consequently, the 

 family name must also be changed. Further study has also led me to the 

 conclusion that the genus Cucullaria Conrad, which is referred to Macrodon- 

 tidce on page 517, should rather be included with the true Arks, in spite of the 

 fact that the hinge-teeth are arranged with much, similarity to those of the 

 Paleozoic group. This similarity is probably only superficial and due to 

 other causes than inheritance from such forms as Parallclodon. 



FAMILY LIMOPSID^. 

 Genus TBINACBIA C. Mayer. 



Trigonocalix Conrad, Am. Journ. Conch., i., p. 12, 1865 (T. cuneus Conr.). 

 Trinacria C. Mayer, Moll. Tert. du Mus. de Zurich, Hi., p. 62, 1868. 

 Trigonocirlia Desh., Descr. An. s. Vert, bassin de Paris, i., p. 838, 1860. 

 Not Trigonoccelia Nyst and Galiotti, Bull. Acad. Brux., ii., pp. 287, 347, 1835. 



This curious little genus is represented in the Claibornian by T. cnnetis 

 Conrad (+ carinifera Lea), T. pectuncularis Lea, and T. ledoidea Meyer, which, 

 described from a single worn valve, seems rather close to pectuncularis. The 

 name Trigonoccelix, used by Conrad in his catalogue of Eocene fossils, appears 

 to have been a typographical error ; if not it would antedate Trinacria, though 

 no diagnosis was given. 



Trinacria Meekii n. s. 

 PLATE 32, FIGURE 17. 



Oligocene of the Chipola beds, Chipola River, Calhoun County, and of 

 the Alum Bluff beds, Oak Grove, Santa Rosa County, Florida; Dall and 

 Burns. 



Shell small, solid, moderately convex, sculptured only with fine concentric 

 lines; anterior end rounded, posterior somewhat shorter, more pointed; beaks 



