— G — 



3. The examples were very well chosen with reference to 

 variety, distinetive characters, age, and size, and have been 

 kept in a very good state of preservation. 



Some of the genera, chiefiy amongst Land SJiells, con- 

 tain many species. The genus Helix contains about 371 

 named species out of 614 inMiss Catlow's Conchologisfs No- 

 menclator; Bulimus 121 species; Clausilia 50 species ; Cy- 

 clostoma 61 species; Pupa 36 species, etc. Of the convoluted 

 shells, the genus Conus contains about 73 species; Cyprsea 

 64 species; Oliva 59 species. Of the Canaliferous, there are 

 38 species of Murex, and 24 species of Triton. Of the Pur- 

 puriierous, there are 24 specics of Purpura, 17 species of 

 Cassis, 11 species of Dolium, and 40 species of Buccinum 

 and Nassa. Amongst the Nymphacea there are about 30 

 species of Tellina, and 10 species of Lucina 5 of the Venuses 

 38 species, and Cytherea 18 species ; Arca 23 species; Car- 

 dium 25 species; etc. 



4. Mr. Mamo's Collection is not classified; but from the 

 Catalogue I have prepared, I have extracted this Prospectus, 

 (which being rather long I shall not read without your leave), 

 arranged according to Woodward's natural Classification. 

 I have followed the highest authorities at home — such as 

 the late Professor Forbes' in the History of British Mol- 

 lusca, and Professor wen's in the Hunterian Lectures and 

 Catalogue — in choosing Woodward's, in preferencc to other 

 more recent natural Classifications. Moreover, as many of 

 the genera have been recently separated and subdivided on 

 account of generic and t}'pical differences into other genera 

 and subgenera, I have profited in this respect by Chenu's 

 Malacholo^y in adopting thosc alterations, which are gcne- 

 rally admitted, in this arrangement. For instance, I have 

 separated from the Tritons on Chenu's authority, the T. cla- 

 thratus, Sowb., and T. anus, Lam., which with T. ridcns, form 

 the subgenus Persona, Montf., typically different from all 

 other Tritons in the denticulation and distortion of the inner 

 lip, which give them really the appearance of a mask. The 

 Dolium pomum, Lam., and D. latilabrum, Kiener, compose 

 at present the genus Malca, Valcnciennes, widoly different 



