10 



MINERAL CONCHOLOGY. 



deatli in 1822, when a considerable portion of the fourth vo- 

 lume had been published. For some time previously to this 

 sad event, it had fallen to my lot to describe the M^hole of the 

 shells, and now I was obliged, in addition, to engrave the 

 plates, a few only having been done in advance by my father. 

 At the conclusion of the sixth volume, circumstances induced 

 me to close the work, with a view to commencing it again in 

 a form more agreeable to the wishes of geologists ; and this 

 intention has not been lost sight of, for a continual expense 

 has been incurred in collecting new materials, and many 

 thanks are due to my friends in responding to my request ; 

 still however the whole of the indexes are not published, and 

 chiefly because I have been induced to give up my time to- 

 wards forwarding the immediate objects of the leading geo- 

 logists of England, by yielding them the best assistance my 

 humble talent would permit. 



The sale of the 'Mineral Conchology' has only been about 

 400 copies, above one fourth of which number has been sent 

 abroad. The encouragement therefore for carrying on the 

 work has hitherto been not very great ; but your having di- 

 rected public attention so strongly to it, and the anxious 

 wishes of my friends, have stimulated me to determine now 

 upon its immediate continuation, which I hope to effect in a 

 month from this time. 



I fear I have said too much about myself, but you will 

 perhaps excuse me if I say a few words in reference to the 

 translation. Mons. Agassiz has not always improved the ge- 

 neric characters by the alterations he has made. For instance, 



under Soleu he says, "Car. Gen. Bivalve longitudinale," 



instead of transversely elongated. In Ammonites the word 

 " dorsal" is inserted whereas the siphon is truly ventral ; &c. 

 Neither has he embodied all the corrections given in the lat- 

 ter part of the work, indeed he seems not to have consulted 

 the index in No. 105 in any case. There Cassis is referred 

 to Cassidaria ; Modiola parallela to Plagiostoma elongatum; 

 Helicina to Rotella; Helix carinatus to Pleiirotomaria, whe- 

 ther correctly or not, may be a question, but certainly it is 

 not a Cirrus, (Mons. Agassiz proposes to name it Cirrus Sow- 

 erhy) ; Venus to Cyprina ; Murex to Fusus ; and Vivipa- 

 ra to Paludina : but Agassiz has introduced several of these 

 alterations as his own. Still, some of his remarks are good, 

 and will not be lost sight of by me. 



I am. Sir, 



Your's, &c. 



J. D. C. SOWERBY. 



Editor Magazine of 

 Natural History. 



