105 
CARDIUM Parkinsoni. 
TAB. XLIX. 
Spec. Char. Gibbose, rather oblique, posterior side 
straightish ; surface slightly rugose, with nearly 
forty longitudinal ribs, having slight transverse 
risings on each. 
This elegant shell is larger and more delicately formed 
than our Cardium edule, or any of its varieties; it is also 
less angular or acute at. the posterior side ; the number of 
striae is generally about thirty-six, with some differences in 
their relief. The transverse rugae, which are most promi- 
nent near the margin, are less numerous than in the common 
Cockle. The inner marginal teeth are distinctly incurved. 
I do not know of a similar Cockle in a recent state, although 
it has but few distinguishing characters : it much resembles 
Cardium maculatum, Lister 328, No. 1 65; from the bay 
of Campechy, which has thirty-one ribs. 
This very neat and perfect specimen was presented to me 
by Mr. Parkinson, who, as a sort of Yolunteer in the Natural 
History of Organic Remains, has been so deserving of 
remembrance, that I felt it a kind of duty to give it his so 
respectable name. 
The Craigs afford some other species, but I have only 
received this from Mr. Parkinson, besides somewhat smaller 
