472 Mr. G. B. Sowerby's Remarks 



This is a fossil species, of which the two valves have been found 

 in considerable abundance, but always separate, in a compact 

 marly stratum, in the department de la Manche in Normandy, 

 and communicated to my father by our very liberal friend 

 C. Duherrissier de Gerville. 



1 had named the above species C. product a ; but since the Paper 

 was read I find it has been described by M. Defrance, and figured 

 in the Dictionnaire des Sciences naturelles under the name of C. an- 

 tiqua, which I have therefore adopted. It is also described in La- 

 marck's Hist. Nat. des Anim. sans Vert. t. vi. part 1. p. 239. 



The delay which has attended the printing of this Paper gives 

 me an opportunity of noticing two or three mistakes into which 

 M. de Blainville and M. de Lamarck have fallen, upon receiv- 

 ing some specimens of the Orbicula norvegica. M. de Blainville* 

 has confounded it with Patella distorta of Mont., and also with the 

 Criopus of Poli, a name given by Poli to the animal alone of the 

 Crania personata ; but he refers it rightly to Patella anomala of 

 Midler, and to the genus Orbicula of Lamarck. 



Lamarck has fallen into the same mistake in referring Poli's 

 Anomia turbinata to his own genus Orbicula ; but, unhappily for 

 science, he is obliged to see with the eyes of others ; and this 

 circumstance will account for his having made a new genus, con- 

 stituted from a specimen sent to him by my father, of the Orbicula 

 norvegica, under the name of Discina, and even for his havino 

 placed it in another family. The genus Discina ought therefore 

 to be wholly erased from Lamarck's Hist. Nat. des Anim. sans 

 Vert. t. vi. p. 236 ; and the description and greater part of the 

 observations under it, might with propriety be transferred, to 

 replace the description of his Orbicula, the observations to which 

 might remain. 



* Bull, des Sciences, May 1819. 



REFE- 



