TRANSACTIONS OF WAGNER 

 I I SO 



TERTIARY FAUNA OF FLORIDA 



Bornia dodona n. sp. 

 PLATE 45, FIGURE 16. 



Oligocene sands of Oak Grove, Santa Rosa County, Florida ; Burns. 



Shell small, thin, compressed, subtrigonal, smooth, brilliantly polished; 

 anterior end slightly shorter, wider, and more rounded, posterior end longer 

 and more pointed ; beaks low, the prodissoconch distinguishable, dorsal margins 

 sloping, basal nearly straight ; right valve with two lamellae bearing knob-like 

 teeth on the umbonal end in front of the beak, a subumbonal obliquely directed 

 resiliary scar, and a posterior lamella, separated by a groove from the dorsal 

 margin ; left valve with two short divaricating lamellae under the beak and a 

 feeble rather distant posterior lamella; adductor scars small, rather high up, 

 interior of the valves faintly, radially striated. Lon. 5.25, alt. 3.7, diam. 1.75 

 mm. 



Resembles B. mactroides Conrad, but appears to be uniformly of a very 

 much smaller size. 



Bornia floridana n. sp. 

 PLATE 45, FIGURE 2. 



Oligocene sands of Oak Grove, Santa Rosa County, Florida ; Burns. 



Shell thin, compressed, smooth, or with faint incremental lines, brilliantly 

 polished, the prodissoconch obvious; teeth short, the anterior left lamella 

 most prominent, the posterior lamella feeble ; hinge normal, form as figured. 

 Alt. 5, Ion. 6.6, diam. 1.75 mm. 



This species is more compressed, less trigonal, and more elevated in pro- 

 portion than B. dodona, as the figure shows. The proportional elevation seems 

 to increase with age. All the valves obtained were more or less imperfect. 



Bornia mactroides Conrad. 

 Lepton mactroides Conrad, Journ. Acad. Nat. Sci. Phila., vii., p. 151, 1834; Fos. Medial 



Tert, p. 19, pi. 10, fig. 5, 1838. 



Erycina mactroides Orbigny, Prodr. Pal., Hi., p. 115, No. 2153. 

 Kellia mactroides Conrad, Proc. Acad. Nat. Sci. Phila., vol. i., p. 310, 1843. 



Miocene of Maryland, near Easton, at Barker's landing, Choptank River, 

 Dover Bridge, Governor's Run, and Peachblossom Creek ; Burns, Harris, and 

 Maryland Geological Survey. 



This species differs from the next in its more triangular form, pointed ends, 

 mesially compressed disk, and more cuneate vertical section, the shell being 

 quite inflated dorsally and compressed towards the base. 



