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TEREBRATULA cordiformis. 
TAB. CCCCXC y.—Jigs. 2 and 4. 
Spec. Char. Heart-shaped, front much elevated 
with a deep sinus in the margin ; sides rather 
convex, sharp-edged ; middle ornamented with 
several acute furrows reaching almost to the 
beaks. 
This differs from the last in being much more tumid in 
the middle, and in having 3 or more sharp angular fur- 
rows extending from the middle of the large marginal 
sinus almost to the beaks : it is very variable in magni- 
tude. 
Found in the Mountain Limestone of Ireland, but not 
plentiful. 
TEREBRATULA reniformis. 
TAB. CCCCXCVI. —Jigs. 1, 2 , 3 , and 4. 
Spec. Char. Reniform, middle furnished with 
three or four longitudinal rounded ridges, ter- 
minated by acute plaits in the much elevated 
margin of the front ; sides inflated below the 
entire edges. 
A much rounded, almost two-lobed, inflated and more 
or less depressed shell. The form of the ridges and in- 
termediate furrows is very remarkable, being rounded, 
while the corresponding notches in the margin are acute- 
angular : the peculiar form of the sides of the beaked 
valve, which are inflated so as to hang below the edges, 
will distinguish all the varieties of this species. 
Very abundant in the Mountain Limestone of Dublin 
and Cork. 
