BWALVE SHELLS. o7 



tt ears unequal, and having one of them generally ciliated with spires with- 

 in ; f f t valves g-ibbous on one side. 



Ostrea Lavis. — The Smooth Ostrea. Plate II. fig. 2. 

 (Pecten Laevis, Lamarck.) Shell thin, flat, sub-orbicular, and 

 pellucid, longitudinally and transversely striated ; one ear con- 

 siderably larger than the other; colour various, sometimes orange, 

 dark pink, &c. Not uncommon on the coast of Northumber- 

 land. The striae on this shell are so minute, that they can seldom 

 be seen with the naked eye. 



F Longitudinal and transverse striae, h h ears or auricles. 

 Ostrea Opercularis. — The Lid Ostrea. Plate VII. fig. 14. 

 Ears nearly equal ; shell with about twenty rounded ribs finely 

 striated longitudinally and transversely ; beautifully variegated 

 with red, orange, purple or brown ; upper valve somewhat con- 

 vex. Inside pure white. Three inches long. Inhabits the 

 British Seas. 



The Ostreae inhabit the ocean ; some lurk in the sand in large beds, 

 others adhere to rocks, and some to the mangrove trees which overhang the 

 sea on the shores of the West Indies. 



The Edible Oysters of Britain, are said to be superior to those of all otlier 

 countries, and are common on many of our coasts. Indeed, this country has 

 been noted for oysters from the time of Juvenal, who flourished in the be- 

 ginning of the second century j in satirizing Montanus, an epicure, he says : 



He, whether Circe's rock his oysters bore. 



Or Lucrine lake, or distant Richborough's shore. 



Knew at first taste. 



The luxurious Komans were very fond of oysters, and had their layers or 

 stews for them as we have at the present time. Sergius Orata was the first 

 inventor, as early as the time of L. Crassus the orator. He did not make 

 them for the sake of indulging his appetite, but through avarice, and enjoyed 

 great profits from them. Orata got much credit for his Lucrine oysters, for, 

 says Pliny, the British were not then known. 



The oyster is a very entertaining object to those who are fond of micros- 

 topic investigation. In the clear liquor around the animal, many minute, 

 round, living animalcules have been found, whose bodies being conjoined, 

 form spherical figures with tails, not changing their place otherwise than by 

 sinking to the bottom, being heavier than tlie fluid ; these have been fre- 

 quently seen separating, and coming together again. In other oysters, 

 animalcules of the same kind were found not conjoined, but swimming by 

 one another, where they seemed in a more perfect state, and were judged 

 by Leeuwenhoek to be the animalcules in the roe or semen of the oyster. 



A female oyster being opened, incredible numbers of small oysters were 

 seen, covered with little shells, perfectly transparent, and swimming along 

 slowly in the liquor ; and in another female, the young ones were found of 

 d brown colour, and without any appearance of life or motion. 



In the month of August oysters are supposed to breed, because young 

 ones are then found in them. Leeuwenhoek, on the 4th of August, opened 

 D 



