142 
PETRICOLA laminosa. 
TAB. DLXXTII. 
Spec. Cuar. Ovate, gibbose, ornamented with erect 
concentric lamine ; posterior side subcunei- 
form ; one broad bifid tooth in the left valve, 
two small teeth in the other. 
eee ene 
Tis is the largest species of Petricola known; the la- 
mine upon its surface are entire, rather thick, and tole- 
rably close set ; they distinguish it from every other. 
Found by the Rev. G. R. Leathes in the Suffolk Crag ; 
who has kindly allowed us the use of the only specimens 
he has. 
Fig. 1. represents two views of the left valve of a re- 
gularly grown shell: Fig. 2. the same valve from a dis- 
torted individual: Fig. 3. the inside of the right valve, 
also a distorted shell. 
