66 
cave space, in the middle of which is a slight elevation 
proceeding from a minute sinus 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. CCCCXLVX .—Jigs. 2 and 3. 
Spec. Char. Elliptical, subrhomboidal, rather 
depressed ; front truncated and indented ; 
edges sharp. 
Var. /3, Small, blunt edged, and obovate* Eig. 3. 
Valves nearly equal, not very convex, rather concave 
near the indented front edge ; 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 have also seen another from Bristol. 
Fig. 3 is the small variety, sent by Mr. Moore from the 
neighbourhood of Dublin. All come from the black 
Limestone. 
TEREBRATULA cornuta. 
TAB. CCCCXLV l— fig 4. 
Spec. Char. Short, convex, with blunt edges, 
four lobed ; the two middle lobes produced, 
the others very short. 
Irregularly five sided ; 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 each or which they are 
equal ; the beak is short, incurved, and has a sharp keel 
on each side of it ; the surface is smooth and shining. 
One of 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 Ilminster, by the kind- 
ness ofE. Strangeways, Esq. 
