304 PALEONTOLOGY OF OHIO. 



Genus EDMOiTDIA, DeKoninck, 184 i. 



(Anim. Foss. Carb. Belg., 66.) 



Edmondia? tapesiformis, Meek. 



Plate 13, fig. 6. 



Shell longitudinally suboblong-oval, about once and a half as long as 

 high, rather compressed; posterior side rather obliquely rounded; an- 

 terior side very short, rounded, or subtruncate; basal margin forming a 

 long nearly elliptic curve ; dorsal very straight, and but very slightly 

 declining posteriorly ; beaks anterior, oblique, and scarcely rising above 

 the cardinal margin; umbonal slopes not angular or even prominent. 

 Surface ornamented by regularly arranged, raised concentric lines or 

 small ridges, separated from each other by wider furrows. 



Length, 1.81 inches; height, 1.10 inches; convexity, about 0.46 inch. 



This species is only referred to the above mentioned genus with great 

 doubt, as nothing is known in regard to the nature of its hinge or other 

 internal characters. It seems to be a thin shell, but does not present 

 the general aspect of Allorisma, Sanguinolites, Sedgwichia, or any of the 

 allied groups, being much more compressed, and apparently closed all 

 around. So far as can be determined from the only specimen yet seen, 

 the cardinal margin does not appear to be inflected as in the most of the 

 palaeozoic t3^pes believed to belong to the Anatinidae. In a side view it 

 presents somewhat the appearance of a shell figured by Prof. McCoy, 

 under the name Mactra ovata, in his Synop. Carb. Fossils of Ireland, pi. 2, 

 fig. 4, excepting that it is proportionally about one-third longer and 

 more compressed. In its proportional length and height it agrees more 

 nearly with another form figured in the same work under the name Pal- 

 lastra ovalis, but its extremities are more regularly rounded. 



Locality and position: Richfield, Summit county, Ohio. Waverly series of the 

 Lower Carboniferous series. 



Genus CARDIOMORPHA, DeKoninck, 184 1. 



(Anim. Foss. Carb. Belg., 101.) 



Cardiomorpha subglobosa, Meek. 



Plate 15, figs. 6a, b. 

 Shell subglobose, or a little higher than long, with convexity nearly 

 equaling the length ; anterior and posterior margins rounding regularly 

 into the base, and forming with the latter more than three-fourths of a 



