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12. Carpita optonea, J. Sowerby. Tab. XXII, fig. 14, a, 4. 
VENERICARDIA OBLONGA, J. Sow. Min. Conch., t. 289, fig. 2, 1821. 
Spec. Char. C. Testa transversd, oblonga, crassiusculd, subquadrangulari, valdé ine qui- 
laterali ; radiatim costatd, costis 13—15, elevatis, tuberculosis ; umbonibus depressis ; lunuld 
parva, cordiformi ; cardine crassiusculo. 
Shell transverse, oblong, subquadrangular, thick, strong, very inequilateral ; costated 
with 13—15 tuberculated ribs; beaks depressed ; lunule small, heart-shaped, depressed ; 
hinge moderate. 
Length, +3ths of an inch; height, } an inch. 
Localities. Barton, Hordle, Highcliff, Bracklesham (/dwards). 
This is a pretty species, and abundant at Barton. The umbo sometimes extends 
beyond the pedilateral margin, and the hinge is quite at the extremity of the shell; the 
ventral margin in some specimens has a slight curve inwardly, with the impression of 
adductors large and distinct; the ribs are covered with nodules, and they are about as 
wide as the depressed spaces between them. 
Mr. J. Sowerby, in ‘ Min. Conch.,’ says that it occurs in France, but I have not been 
able to ascertain its locality. 
In two or three of these oblong species there is a small distinct denticle on the pedal 
side of the hinge in the left valve, with a depression for its reception in the right; this is 
immediately above the impression of the pedal muscle. Fig. 18, Tab. XXII, represents 
what I at first thought might be specifically distinct, the umbo projecting beyond the 
margin, with more depressed and rounded ribs, which are less tuberculated ; but I believe it 
to be only a variety (C. od/onga, var. transversa). It is from the Fluvio-marine at Hordle, 
Fig. 10, Tab. XXII, represents another form, probably, of this species ; it had in MS. 
the name C. serratina. It is not so tumid as the normal form, it is less transverse, and 
the costze are more regularly nodulous. I think it is only a variety It was found at 
Mead End, Headon Hill, and Barton. 
Fig. 11, Tab. XXI, represents a small specimen in Mr. Edwards’s cabinet, which at 
one time I thought might be a distinct species; but having only one specimen, and that, 
perhaps, distorted, I have considered it as a variety (C. oblonga, var. trapezoidalis). It is 
from High Chiff, Barton. 
13. Carprra paucicostata, Sandberger. Tab. XXII, fig. 6, a, 4, c. 
Carpita pAuctcostata, Sandb. Conch. d. Mainz. Beckens, p. 337, t. 24, f. 6, 1863. 
Spec. Char. C. Testé rotundato-trigonuld, crassd, convexiusculd, costatd, costis paucis, 
elevatis, nodosis, distantibus ; subinequilaterali ; lunuld brevi, concavd ; umbonibus obliqus 
