BIVALVIA. 75 



Cypricardia Bathonica, jy Orb. Tab. VII, fig. 8, 8«, b, c. 



CypBiCABDiA Bathonica, IfOrhigny. Prodrome de Pal^ont., p. 308, 1850. 



Tesid ovato, transversa, inaquilaierd, turgidd, cordiformi, postico angulatd et elongato 

 lavigatd ; umbonibus magnis obliquis recurvis, car dine bidentato dentibus lateribus distan- 

 tibus elongatis ; margine integro postice subsinuato. 



Shell ovate, transverse, inequilateral, ventricose, heart-shaped, posterior side angulated, 

 elongated and smooth ; umbones large, obhque, slightly recurved ; hinge with two large 

 cardinal teeth and one distant elongated posterior lateral tooth ; margin of the valve entire, 

 slightly sinuated posteriorly. 



This species approaches near to C. cordiformis, Deshayes, but it is more oblique or 

 lengthened posteriorly ; it occurs rather abundantly in the bed of coarse planking. 



Height, 21 lines; length, 27 lines; diameter through the valves, 17 lines. 



Localities. Minchinhampton Common ; Ponton, Lincolnshire ; in the Fuller's earth 

 of Box Tunnel, near Bath. 



Cypricardia rostrata, Sow. sp. Tab. VII, fig. 9, 9«, b. 



IsocARDiA ROSTRATA, Sow. Mill. Con., t. 295, f. 3, 1819. 



— — Goldf. Petref., p. 210, t. 140, f. 12, 1840. 



— — Morris. Cat., p. 88, 1843. 



1 Cabdium Beaumonti, If Archiac. Mem. Soc. Geol. Fr., tom. v, t. 26, f. 4, (nucleus,) 



1843. 



Testa subtrigond, convexd ; umbonibus angulatis, antemedianis,prominulis ; lunula parvd 

 excavatd; latere antico rotundo, postico truncato angulo obliquo carinato ; dorso Icevigato ; 

 lineis incrementi paucis, irregularibus. 



Shell subtrigonal, convex ; umbones angulated, prominent, anterior, and incurved ; 

 lunule small, excavated; anterior side rounded, posterior side truncated and somewhat 

 concave, its inner border forming a prominent and obtuse angle ; the surface of the shell 

 is smooth, and marked only with a few faintly impressed lines of growth. 



The hinge line posteriorly is nearly horizontal, forming an angle with the posterior 

 sloping margin, the margin itself forming an acute angle with the inferior borders. 



Height, 10 lines; lateral diameter, II lines ; diameter through both the valves usually 

 about 8 lines, but the latter measurement varies in individuals. 



It occurs abundantly in the form of nuclei in the upper portion of the Great Oolite, and 

 very rarely with the test preserved, in the shelly beds of the formation. The figure of 

 D'Archiac has a greater height than is exhibited by our specimens, and the umbones are 

 less inclined forwards, but looking at the great varieties of figure which the nuclei assume, 

 we do not see any sufficient reason to regard it as a distinct species. 



Localities. Minchinhampton Common ; Oxfordshire ; Northamptonshire. 



