66' 



cave space, in the middle of whic^h is a slight elevation 

 proceeding from a minute simis in the edge of it. 



From the Derbyshire Limestone ; the specimen 

 figured formerly belonged to Mr. Martin, who says the 

 species is common, particularly at Eyem and Middleton ; 

 we have it also from near Matlock, on the road from Derby. 



TEREBRATULA hastata. 

 TAB. CCCCXLVL— ^^5. 2 and 3. 

 Spec. Char. Elliptical, subrhomboidal, rather 

 depressed ; front truncated and indented ; 

 edges sharp. 

 Var. ^, Small, blunt edged, and obovate- Fig. 3. 



Valves nearly equal, not very convex, rat'^ier concave 

 near the indented front e(k^e ; the width is about two 

 thirds of the length. The variety /3 is always smaller, 

 shorter, and deeper; its small valve is also less concave 

 towards the front. 



The large figure represents a specimen from Limerick, 

 presented by S. Wright, Esq. the smaller one, another 

 from near Dublin. 1 iiave also seen another from Bristol. 

 Fig. 3 is the small variety, sent by l\!r. Moore from the 

 neighbourhood of Dublin, All come from the black 

 Limestone. 



TEREBRATULA cornuta. 

 TAB. CCCCXLVl.— ^V 4. 

 Spec. Char. Short, convex, with blunt edges, 

 four lobed ; the two middle lobes produced, 

 the others very short. 



J-RREGULARLY five sidcd ; the two sides that meet at the 

 beak are convex, the others concave, the front very 

 deeply so ; the lateral lobes are rather obscure, the others, 

 obtusely pointed, and forming ridges that diverge from 

 near the centre of the valves, in eacii or which they are 

 equal ; the beak is short, incurved, and has a sharp keel 

 on eacii side of it ; the surface is smooth and shining. 

 One oi the prominent lobes is often less produced than 

 the other, a resemblance is then formed to the unequally 

 elongated horns of a snail, whence the name. 



From the coarse Limestone of llminster, by the kind- 

 ness of E. Strangeways, Esq. 



