Bibliographical Notices. 75 



The authors have exercised a wise discretion in employing so large 

 a proportion of their names in a ^w^generic sense. For although this 

 extreme subdivision of natural groups may be useful in a few great 

 collections, and convenient in special or elaborate monographs ; yet, 

 for ordinary purposes, a much smaller number of divisions is suf- 

 ficient. The generic names in general use do not exceed 300 for the 

 whole of the living Encephalous Mollusca ; and we are quite sure 

 that no conchologist, or brace of conchologists — not even the authors 

 themselves — will ever learn the eleven hundred and odd names here 

 propounded ; especially since so many of them are constructed in a 

 form which takes no hold of the memory, e. g. Neda, Aspa, Thala^ 

 Ziba, Dinia, Sarnia, Popnia, Elara, Elaira^ Mesa, Alaba, &c. &c. 

 To the exoteric public this style is by no means attractive, nor is the 

 taste of naturalists in general so far behind that of the rest of the 

 world as to lead them to prefer Adanson as a model. 



Of the 18 genera and 121 new subgenera proposed by the authors, 

 there is not one which calls for special notice ; they appear to be 

 founded on empirical characters, such as we should have regarded as 

 possessing at most a specific importance. 



The list of species appended to each genus and subgenus is one of 

 the principal features of the work. It will be extremely convenient 

 to those who have large collections, and may some time form the 

 basis of what is very much wanted — a Geographical Catalogue of 

 Shells. Of the 13,300 species, probably less than half are in the 

 British Museum ; but a larger proportion is in the Cumingian col- 

 lection, which the authors are understood to have chiefly used. High 

 as this number is, the land snails might now be increased by 1000 

 names, and some marine genera (like Cyprcea) are far from com- 

 plete ; but many of the lists are swelled by the introduction of syno- 

 nyms, varieties, and fossils, and will require considerable revision. 



The space occupied by the lists of species exceeds one-fourth part 

 of the work ; while nearly another quarter is occupied with headings 

 of various kinds. Thus before reaching the "Woodcock Murex " we 

 encounter the following inscriptions : — 



Class, Gasteropoda. 



Subclass, Prosobranchiata. 



Order, Pectinibranchiata. 



Suborder, Proboscidifera. 



Family, Muricid^. 



Subfamily, Muricin^. 



Genus, Murex. 



Subgenus, Haustellum. 



Species, haustellum. 



The objection to this, however, is not so much the space it occupies. 



