38 ostreid^e. 





place, and especially in the earlier states of growth, have 

 been carefully examined and compared, many recent 

 species may become " extinct " in consequence of a re- 

 duction in number, and with great advantage to science. 

 Poli gave the animal the name of Peloris. But that was 

 not an oyster. 



Murice Baiano melior Lucrina peloris, 

 Ostrea Circeiis, Miseno oriuntur echini, 

 Pectinibus patulis jactat se niolle Tarentum. 



Ostrea edu'lis *, Linne. 



0. edulis, Linn. Svst. Nat. p. 1148 ; F. & H. ii. p. 307, pi. liv., and (ani- 

 mal) pi. T. f. 1. 



Body much compressed, although rather thick, of a pale 

 drab colour more or less tinged with brown : mantle nearly 

 circular : cirri arranged in two rows, the outer one of which is 

 double but irregular, and the inner one single : mouth furnished 

 with a pair of large and nearly triangular lips on each side. 



Shell round in its young state, and afterwards spreading 

 out in front or at the sides, with frequently a more or less 

 curved outline, usually compressed, rather thick, of a dull 

 appearance outside : sculpture, foliated or scaly ; lower valve 

 sometimes strongly ribbed lengthwise ; the entire surface of 

 the shell when young is microscopically shagreened ; lines of 

 growth well marked: colour yellowish -brown : margins thin 

 and closely appressed or squeezed together, usually semicir- 

 cular in front and more or less rounded at the sides : beaks 

 small, divided by the cartilage, which is thick and very strong, 

 light-brown or horncolour, and supported on each side by a 

 short ligament of a dark olive-green : hinge-line narrow and 

 nearly straight : hinge-plate thick : inside white and pearly ; 

 lateral edges (especially of the flat valve) finely crenulated or 

 notched on the upper part : muscular scar obliquely transverse, 

 pear-shaped or slightly incurved above. L. 3. B. 3*5. 



Yar. 1. parasitica. Shell much smaller, flatter, and more 

 glossy ; colour purplish or greenish-brown, with streaks of a 

 darker hue radiating from the beaks. 0. parasitica, Turt. 

 Conch. Diet. p. 134, f. 8. 



* Eatable. 



