G8 Mr. (ji. B. Sowerby on Ilinnites. 



be seen in the possession of collectors, particularly in Paris, that 

 the naturalists of that metropolis had a fair opportunity of be- 

 coming acquainted with its characters. Not so, however, tjie 

 English collector, for the few specimens which found their way io 

 this country were confined to one or two collections and were 

 consequently scarcely known. The first notice that we find ia 

 connection with the genus in this country, has been given very 

 lately in the Annals of Philosophy by Mr. Cray, who has de- 

 scribed a recent species from a specimen in the British Museum. 

 It cannot be considered as surprising that both M. Defrance, who 

 proposed the genus, and Mr. Gray, who thus added to the informa- 

 tion concerning it, should have mistaken its real relations, the 

 first, who as we have before stated, ranked it between the Spou- 

 di/liis awd Ostrea, having only some fossil valves; and the latter 

 who places it in the Spondylida'^ having described only a worn 

 individual. It will be seen in the sequel of this communication 

 that it rightly belongs to the Pectinidce, and that it is hardly 

 possible to separate it as a genus from Pecten,* but were it to be 

 established as a genus, it must be placed in the PcctinidccA 



The examination of a number of specimens of three or four 

 decidedly congeneric species have conducted me to the results 

 which will be explained in the following observations. First, I 

 must inform naturalists that one of our commonest British shells, 

 a shell to which neither M. Defrance nor Mr. Gray has referred, 

 belongs to this genus, namely Pccten Piisio of some, P. distortus, 

 of others. The singular manner in which this shell, almost con- 



* I am informed tliat Mr. Gray, immediately upon his return fronj Paris, 

 lias stated that he is convinced that Pecten distortus is of the same genus with 

 Jlinnites; as well as that the alteration from Ilinnites to Ilinnita is an error. 



+ I cannot doubt the fact of the Pectinidce being all naturally aflixed by a 

 byssus, in the same manner as the Mytilidcc ; indeed I have seen so many 

 proofs that I consider it as perfectly settled. It is no more difficult to account 

 for the large number that we eee, without their byssus, than it is to account 

 for the immense quantities of muscles we see on some shores, also without 

 their byssus. If indeed, it be asserted that we sometimes see the muscles 

 thrown on the shore with their byssus, and that we never fee the Pec/ine* with 

 theirs, we have only to suppose that the byssus of the Pectinidce is not so 

 strongly affixed to the animal as llmt of th(! muscle: wo kiiow, moreover, that 

 it is much mor«' slender. 



