MOLLUSCA. 29 



served that, in some genera, the valves do not close or unite 

 all round, but that, at certain places, the shell remains in 

 part open. Such shells, in modern language, are said to 

 gape. 



The system of the celebrated Linnaeus, which ought now 

 to be mentioned, is too well known in this country to de- 

 serve particular notice. In many of the other departments 

 of Zoology he effected the most important alterations ; but 

 his attempts to reform the science of conchology, were far 

 from being equally successful. To the subject he never 

 was much attached, nor does he appear to have availed him- 

 self sufficiently of the labours of those authors whom we 

 have mentioned, and of others who preceded him. The 

 primary divisions which he employed, were those which 

 Major had established, and his genera, with a few excep- 

 tions, were those in common use. His merit as a concho- 

 logist rests entirely on the accurately defined terms, the 

 concise specific characters, and the convenient trivial 

 names which he employed and introduced. The particu- 

 lar consideration of the Linnaean genera, and the subse- 

 quent changes which have been introduced into them, will 

 form the subject of a separate section. 



For some time after the publication of the Systema Na- 

 turce, the illustrious Swede enjoyed a very dangerous repu- 

 tation. All his arrangements were regarded as of such high 

 authority, that it was considered as impious to attempt to in- 

 troduce any change ; so that conchology, and along with it 

 the study of the mollusca, according to the artificial method, 

 remained a long time stationary. At last in France, a coun- 

 try which refused to submit to the fetters of the Linnaean 

 school, several new systems were proposed, which had for 

 their object the restoration of those well-founded genera, 



