153 



which is extrafted from Bidiop Sprat's Hljlory of the 

 Royal Society, p. 307. ■* 



Oflrea ftriata. PuU. Cat- Doyfct. p. 36. Striata. 



Don. Br. S/ielli: ii. t. 45, 



Tiirt. Lin. iv. p. 275. 

 Oltreum ftriatum. Da Cojia. p. 162. t. 11. f. 4. 4. 



Ljjler Conc/i. t. 202. 203. f. 36. 37. 



3. Angl. t. 4 f. 27. 



O. with a fub-orbicular fliellj marked with fine, irre- 

 gular, undulated, longitudinal, rib-like ftriee; umbo very 

 fmall, placed near the top, a little furrounded by the mar- 

 gin : fuperior valve lefs convex than the inferior : colour 

 white. Infide fmooth, gloffy M'hite, with a pearlaceous 

 hue; the hinge is a fmall cavity under the beak; a little 



below which is an opaque, chalky white fpot, of an oval 

 fhape. Diameter rarely exceeds one inch and a half. 



This fpecies is fubjeft to great variety in fliape like the 

 common oyfter, and is frequently didorted and fmuous; 

 but is never plated or laminated like that fhell. Small 

 fpecimens are often ftrongly ribbed with fmaller interme- 

 diate ftriae, and the margin angulated by the ribs ; colour 

 mottled, faint rufous-brown and white. 



This fhell, which was firft noticed by Do61or Lister, is 

 not unfrequently found on fome parts of our coafl; but 

 moflly fingle valves, and by far the greateft part that of the 

 under or concave : thefe having loft the ftrias by being much 

 worn, are fometimes confounded for the Anomia Ephippium. 



X GEN. 



