Mr. Westwood o?a the Affitiities of Clinidium. 213 



branch of science may be observed in the title of a new work recently 

 advertised by Mr. Children and Mr. Gray, which professes to be " An 

 Introduction to the Study of Recent and Fossil Shells, and the Animals 

 which inhabit them," a title which clearly cannot be verified by the work 

 itself, in relation to fossil shells. 



But enough has been said to shew the entirely unsettled state both of 

 the opinions and language of recent authors on shells and their inhabitants, 

 and to evince the necessity of establishing some more precise and definite 

 system of conchology, upon principles which, if shells are still to be 

 considered worth preserving and receiving names, should be immediately 

 derived from the shells themselves. 



It is well known that a system of conchology, or a method of classing 

 shells, has been proposed by M. de Blainville, but adapted in some de- 

 gree to the classification of the animals. He has, however, introduced 

 two distinctive characters, the operculum and the epidermis, both of 

 which, from the unfrequency of their continuance with the shell, must 

 generally become unavailable. There has also been a purely concholo- 

 gical work produced by a Danish naturalist, Mr. Schumacher, which has 

 no reference to the molluscous animals. An analysis of this work 

 would not render the pages of the Zoological Journal less generally inte- 

 resting than they are at present, and might afford some useful hints to 

 Mr. Sowerby in preparing his promised work on the Species of Shells. 



Art. XXXIII. On the Affinities of the Genus Clinidium of 

 KiRBY. By J. O. Westwood, Esq., F.L.S., ^'c. 



When we contemplate the immense number of insects already sup- 

 posed to be contained in our cabinets, estimated by Mr. MacLeay to 

 amount at least to 100,000, and when we are aware that it is the opinion 

 of sorae eminent authors that this number is but one-fourth part of the 

 species actually in existence, (an opinion which appears to be well 

 founded, from the number of new species which the arrival of every col- 

 lection adds to our store,) the remarks which the entomologist occasionally 



