Mr, Martin*; Account offome Specks of Fojil Anomia?. 45 



DESCRIPTION. 



Anomia (cufpidata), tefta conica fulcata : valvula altera con- 

 vexa, nate incnrvata : altera pyramidata, magno foramine tri- 

 gonali. Tab, 3. 



Sharp-pointed conical Anomia. 



The general figure of this fhell is conical. 



The beaked or under vahe y as it is ufually called, is convex, broad 

 (its greateft extent being from fide to fide), and wrought with lon- 

 gitudinal ribs, which are clofely fet, thick, prominent, and crofled 

 by a few flight concentric wrinkles, marking, apparently, the 

 growth of the {hell. The middle rib is much larger than the reft, 

 forming a high convex ridge down the centre of the valve, increafing 

 in breadth from the beak to the margins, which in that part are 

 undulated or waved. The number of ribs, including the middle 

 one, about twenty-nine. The beak is fmall pointed, and curved 

 over the hinge. 



The hinge lies on a perfect flraight line, extending the whole 



breadth of the fhell. 



The upper vahe is pyramidal, gradually tapering from a broad 

 bafe, formed by the other valve, to a fine point or apex, which is 

 the centre or middle part of the valve produced and acuminated. 

 The back, or that portion of the pyramid proceeding from the mar- 

 gins, is rounded, longitudinally ribbed, and indented with a deep 

 concave groove or /ulcus, correfpondent to the ridge in the under 

 valve. The groove and ribs are eroded by a few ftrong but diftant 

 wrinkles. The front, or that part which extends from the hinge to 

 the apex, is flat, fmooth, and perforated; in figure it nearly ap- 

 proaches to an equilateral triangle. The perforation is very large ; 

 it runs through the middle of this fide of the valve, and refembles 

 6 * a lon S 



