90 The Pearl Oyster of Ceylon, [no. 5, new series, 



depths of the sea ; and latterly, I hare used large canoes (ballams) 

 for the same purpose ; — lastly, though perhaps of most importance, 

 I have had unexpected facilities of observation among the several 

 small beds of Oysters found in the inner Harbour of Trincomalie. 

 They are found of all ages and sizes, and various depths and dif- 

 ferent kinds of banks ; so that no Naturalist has perhaps ever had 

 the same opportunities of observing the habits of the Pearly Mol- 

 lusc, as I have at present. 



I cannot do better, than correct at the outset, some popular 

 errors regarding the anatomy of the Pearl Oyster ; and this I may 

 perhaps do most simply, by describing, in a popular form, the ex- 

 ternal and internal structure of the species of Mollusc producing 

 the best Pearls of Ceylon. 



The Mollusc, generally known as the Pearl Oyster, found in 

 the Banks of Arripo, Chilaw, Trincomalie Harbour, and other 

 parts of the Island, does not belong to the same genus as the edible 

 Oyster of Europe, although, in its internal structure it has a re- 

 semblance to it. The Pearl Mollusc resembles more the Mussel 

 tribe than the Oyster ; more particularly, as it has, like the Mussel, 

 a byssus or cable by which it attaches itself to foreign sub- 

 stances, or to others of its kind. The only source of infor- 

 mation that I know of on this subject, available to the Ceylon 

 student, is to be found in " Lebeck's Account of the Pearl 

 Fishery of Ceylon, 1797," to be seen in the Appendix to Captain 

 Steuart's book. The description Mr. Lebeck gives, is very im- 

 perfect, and excites a smile in the modern Naturalist ; but this 

 imperfection is excusable, in any account written in the infancy of 

 the science of Conchology, and when the Microscope was scarcely 

 ever applied to anatomical studies of shells ; at least not in Ceylon. 

 The most glaring error in that description is the mistaking of 

 "bluish spots" on the foot for "eyes," and the " ovaria" for 

 " lungs." This Mollusc has no eyes ; and the lungs, or gills, are 

 in the front, far away from the stomach, and occupy the middle 

 space between the hinge and the anterior edge of the shell, easily 

 seen when the valves are open ; they look like four, or two pairs, 

 of whitish (in a few specimens the gills are of a black color) semi- 

 lunar combs or bands, stretched from side to side. 



