TRANSACTIONS OF WAGNER 



Q14. 



TERTIARY FAUNA OF FLORIDA 



cent with anterior arm of the right cardinal ; left cardinal large, bifid; pallial 

 sinus well marked. 



This group has representatives in European seas, the West Indies and 

 southeastern coast of North America, the Red Sea, and Indo- Pacific region. 



Genus CJECELLA Gray. 



Cacclla (",niy, 1853, Ann. Mag. N. Hist., p. 43. 

 Type C. Ihi-sJiMii Cray (MS.?); China. 



Shell large, concentrically striate, white, with a thick brown epidermis, 

 well marked pallial sinus, obsolete marginal ligament, and fluviatile or 

 brackish-water habitat. 



This genus was referred to the Mactridce by Gray, but a careful study 

 has convinced me that it stands nearest to Ervilla, and if that genus belongs 

 in the Mesodesinatidce so does Ciecclla ; the soft parts of neither being known, 

 their place is not decisively settled. Its distribution is confined, as far as 

 known, to the Indo-Pacific and Austral region. 



Genus ERVILIA Turtmi. 

 Ewilia Turton, 1822, Brit, liiv., p. 56. 

 Type My a iii/t-iis Montagu ; Britain, South Europe. 



Shell small, concentrically striate, sometimes brightly colored; pallial 

 sinus well marked; ligament obsolete; epidermis inconspicuous; habitat 



marine. 



Er villa chipolana n. s. 

 PLATE 33, FIGURE 10. 



Oligocene of the lower bed at Alum Bluff and the equivalent marl at 

 McCIellan's marl bed, Chipola River, Calhoun County, Florida; Dall and 

 Burns. 



Shell small, inflated, pointed behind, the posterior part slightly longer, 

 the anterior end shorter and rounder ; the base evenly arched, the pallial 

 sinus moderately wide, rounded in front, not reaching the vertical of the 

 beaks; umboncs low, not prominent; the sculpture of rather irregular con- 

 centric threads and grooves, absent from the umbones and frequently from a 

 great part of the valves. Lon. 4.5, alt. 3, diam. 2 mm. 



This species, which is very common in the beds, is readily distinguished 

 from E. concentrica, to which it is most nearly allied, by its more pointed 

 posterior end, its coarser and less regular sculpture, its less conspicuous 

 beaks, and generally smaller size. 



