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647 



TERTIARY FAUNA OF FLORIDA 



Moreover, the name consobrina had been used by d'Orbigny six years 

 earher for a French fossil species, and was therefore not available for the 

 West Indian fossil. Sowerby's diagnosis is not distinctive and would apply 

 equally well to several species. A. incquilatcralis Guppy, from Bowden, is 

 more like his figure than is the present species. 



There are in the Oligocene rocks of Gatun and other localities on the 

 Isthmus of Darien, near Panama, several species of Area of which I have 

 imperfect specimens, some of which are nearly allied and may prove identical 

 with A. halidonata. The A. consobrina of Guppy's papers is the present 

 species, which was erroneously referred to A. floridaiia Conr. by Gabb. 



Scapharca (Scapharca) inequilateralis Guppy. 

 Area ineqtiilafcralis Guppy, Quart. Journ. Geol. Soc. Lond., xxii., p. 293, pi. xviii, fig. 2, 



1866. 



Oligocene of the marls of Bowden, Jamaica; Guppy, Henderson, and 

 Simpson. 



This species is closely related to A. latidcntata Dall, of the Chipola, 

 Florida, Oligocene marls, but may be distinguished from it at once by the 

 shorter, more delicate, and much more numerous hinge-teeth of the Jamaica 

 shell. The latter is also thinner and more elegant in sculpture and less 

 inflated. It somewhat resembles the young of A. hypoincla Dall and A. 

 floridana. 



Scapharca (Scapharca) actinophora n. s. 

 Plate 33, Figure 26. 



Shell subequivalve, ovate, moderately inflated, attenuated behind; beaks 

 low, mesially impressed, much bent forward, situated in the anterior fourth of 

 the length; left valve slightly larger, with about forty squarish, uniform, 

 entire radial ribs, with narrower channelled interspaces, the ribs slightly 

 flatter and wider distally; transverse sculpture of fine, low, equidistant, sub- 

 equal, rather close-set elevated lines which are concavely arched as they pass 

 over the ribs ; sculpture nearly identical on both valves ; hinge-line long, 

 straight, anterior end nearly a right angle, the valve margin evenly rounded to 

 the arcuate base; posterior end narrower, produced; cardinal area lanceolate, 

 wider in front, with six or seven concentric grooves, angular near the beaks; 

 teeth numerous, vertical, larger distally in two series, about thirty-five anterior 

 and fifty-two posterior, separated by a short vacant gap ; inner margins of the 

 valves deeply fluted. Lon. 46, alt. 27, diam. 26 mm. 



