Vl INTRODUCTION. 



To supply, in some measure, this deficiency, the 

 following translation and abridgment of Lamarck's 

 work has been made, containing the substance of 

 three large octavo volumes in French. Two transla- 

 tions, at least, have been made in England, both of 

 which have been consulted. One by Crouch, beauti- 

 fully illustrated, bears a high price, and is not easily 

 obtained. The other by Mr Leach, published in num- 

 bers, in the London Quarterly Journal of Science, &c., 

 1823, is of course seldom to be met with. 



Each of the above translations is illustrated by a 

 figure of the type of each genus. To supply, in some 

 degree, the omission of these engravings, a list of 

 species has been affixed to each genus. The assis- 

 tance which this may render will be readily perceived. 

 The Linnsean genera and species are supposed to be 

 more or less known. Now if we have what is called 

 by Linnaeus, Venus Islandica, and we look at the list 

 of species, we find it, not under Venus, but under 

 Cyprina. Being thus certified of the genus, we study 

 this shell instead of a plate, comparing it with the 

 generic description, and thus have a type of the genus 

 by which to arrange other individuals in our cabinet. 

 Thus we may proceed with other genera and species. 



A plate exhibiting the parts of a shell, Wood's 

 Synopsis of Lamarck's subdivision of the Linnaean 

 genera, an index, showing also the accentuation and 

 derivation of the generic names, and a glossary of 

 technical terms, have also been annexed. 



A few more modern and well characterised genera 

 have been placed in the margin J and other species 

 than those described by Lamarck, have been added. 

 Those at the end of the list, separated from the rest by 

 a dash, are American species, described by Barnes, Say, 



