207 
NUCULA laevigata. 
TAB. CXCIL— Figs. 1 and 2. 
Spec. Char. Transversely elliptical, convex,, 
smooth ; posterior side truncated ; edge en- 
tire. 
Nearly related to N. Cobboldiee, but wider and per- 
fectly smooth : it has not even the striae beneath the 
surface, so usual in other species. The lunette is im- 
pressed, convex, oblong, and occupies the truncated 
part of the posterior side ; it has a pit or compressed 
tooth in the hinge, similar to several other species^ 
Of this I have received fragments from Mrs. Cobbold, 
which were very pearly, although found in the Crag of 
Holywells. The perfect specimens represented are from 
Woodbridge ; they are of the usual colour of the Crag, 
but still betray the once more pearly internal coat. They 
are nearly as perfect as living specimens ; I was glad 
to see them ; they were favoured by Mr. Parkinson. 
NUCULA similis. 
TAB. CXCIL— Figs. 3, 4, and io. 
Syn. Area Nucleus. Brander , p. 40. /. 101. 
Brocchi , II. 480 ? 
Nucula margaritacea. Lamarck Env . de 
Paris, 193 ? 
Spec. Char. Transversely obovate, depressed, ob- 
scurely striated longitudinally ; posterior side 
straight ; lunette imbedded ; concave in the 
middle, oblong ; edge crenulated. 
This differs from the recent British Nucula (Area nu- 
cleus | Linn.) in the angle formed by the two lines of hinge 
