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NUCULA undulata. 
TAB. DLIV.— ^g. 3. 
Spec. Char. Globular, concentrically undulated ; 
posterior side produced,, contracted, pointed. 
Much resembling the last : its width is rather greater 
than its length, and it is a little oblique. 
A cast in pyrites from the Clay at Folkstone. Its 
valves are equal, or it might be referred to Corbula. 
NUCULA amygdaloides. 
TAB. DLIV.— fig. 4. 
Spec. Char. Transversely elliptical, elongated and 
sulcated, compressed ; sides equal. 
The width of this neat shell is double the length : the 
sulci are small, numerous, and regular. 
Found at various periods in Hyde Park, and also St. 
James’s Park : and casts in pyrites have been collected 
in abundance at Southend, by the Rev. Mr. Hope. 
