338 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



commissary at la Teste; Alle'gu, at commissary Martigues; and, finally, 

 to M. the commissary SCnes. We would also express to M. Hardy, at 

 Cette, our sincere thanks for the zeal he has shown and pains he has 

 taken to aid and second us in our efforts. Our thanks are also due to 

 M. Curet, captain; to M. Blanchereau and M. Dutemple. 



APPENDIX. 



ANALYSES OF THE PORTUGUESE AND COMMON OYSTER. 



Portuguese oysters, originally f Iodine ... ^| ,„ . .„. 



- . , *  i  ] t> • - 105 S ram m every 100 grams of 



from Arcachon, or having been mw Bromine., s.. _f ... . f 



, ,. ' , ) „, , . f the soft parts of the animal, 



ported there at least a year. [ Chlorine . I 



»-r ,. t^ , TT f Iodine... 1 



Native Portuguese oysters of Ver- J . i .11 gram in every 100 grams of, 



don. | C £|™V^" ; J the soft parts. 



{Iodine . . - ^ 

 Bromine I ,057 S ram in every 100 grams of 

 Chlorine f the soft parts. 



Note by the Translator. — The resemblance of the Portuguese 

 and American oysters is in some respects most striking. In both, the 

 impressions of the adductors are dark purple, while in 0. edulis it is 

 almost invariably colorless. The muscle of both of the first-mentioned 

 species is much more tender and evidently more readily digestible than 

 that of the latter. 0. edulis is smaller, and in every way inferior to 

 both of the unisexual species. 



The Portuguese oyster differs, however, considerably from the Ameri- 

 can in the form of the snell. The lower valve of the former is much 

 more concave internally than that of the American, and the upper valve 

 is often singularly bent to fit it. The internal-hinge border of the lower 

 valve also frequently overhangs the cephalic end of the internal con- 

 cavity of the latter to an extent rarely, if ever, met with in our species. 



The body-mass is a very conspicuous portion of the soft parts of the 

 Portuguese oyster. It is relatively much thicker from side to side than 

 in any other species I have seen. The stratum of generative tissue is 

 also of an extraordinary average thickness, actually far exceeding in 

 proportional volume the same layer in either the American or common 

 oyster of Europe. 



It appears that the spat of Ostrea angulata, like that of the American 

 species, grows much more rapidly than that of O. edulis. For data re- 

 specting the rate of growth of the spat of the American oyster, see my 

 report, pp. C0-G2, in the appendix to the Annual Report of the Com- 

 missioner of Fisheries of Maryland for 1881. 



