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I 391 



TERTIARY FAUNA OF FLORIDA ""^ 



Lucina pilula C. B. Adams, Contr. Conch., p. 244, 1852. 

 Lucina divaricata Reeve, Conch. Icon. 



Pleistocene of St. Domingo, Gabb ; living from Cape Hatteras, North Caro- 

 lina, to Brazil in ten to sixty fathoms. 



This species can be identified by its extremely small, deep, cordate lunule, 

 its serrate dorsal margins, and frequently by its greater size and solidity. I 

 have seen no fossil specimens ; those reported from the Galveston well and 

 elsewhere on examination prove to be referable to D. qiiadrisulcata. 



Divaricella compsa n. sp. 



Plate 51, Figure 3. 



Pliocene of the Caloosahatchie marls on Shell Creek, Florida ; Burns. 



Shell small, thin, subequilateral, rounded, moderately convex, with rather 

 elevated beaks ; surface sculpture that of the genus, but finer and more even 

 than in any other American species ; line of the chevron-shaped angle narrow, 

 extending from the beaks to a point on the base somewhat in front of the 

 middle of the valves ; lunule rather elongate-lanceolate in shape but very small, 

 and almost wholly confined to the right valve ; margins not denticulated by the 

 external sculpture, but internally very finely crenulate ; hinge small, but the 

 teeth conspicuous, the laterals well marked ; the ends of the hinge-line rounded 

 off. Alt. 1 1.5, Ion. 12.5, diam. 8.0 mm. 



This little shell is distinguished by its sculpture, which is uniformly fine, 

 more so than in even the young of the other species, and by its almost obsolete 

 narrow lunule. The figure given, though in the main accurate, hardly repre- 

 sents the sculpture as sufficiently fine, compared with the other species. 



In closing it may be remarked that the term Cyclas, introduced from the non- 

 binomial Klein by Morch, and adopted by H. and A. Adams and Sj:oliczka, was 

 intended to cover the genus here referred to Divaricella. Conrad, however, used 

 it as a synonym of Lucina, senso lata, and not as the equivalent of this group. 

 The word Cyclas, having been introduced into binomial nomenclature by 

 Bruguiere, and restricted by Link in 1807, is not available for another genus. 



The genus Divaricella is stated by Stoliczka to extend into the Cretaceous, 

 but so far none of earlier date than the Oligocene have been reported in this 

 country. 



Family CORBID^. 

 Genus CORBIS Cuvier. 

 Gafrarium (sp.) Bolten, Mus. Boltenianum, p. 176, 1798. 

 Corbis Cuvier, Regne Anira., ii., p. 480, 1817; sole ex. Venus fiiiibriata Linne, S. N., x., 



