10 
MINERAL CONCHOLOGY, 
death 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 whole 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 Solen he says, u 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 para llela to Plagiostoma elongatum; 
Helicina to Rotella; Helix carinatus to Pleurotomaria , whe- 
ther correctly or not, may be a question, but certainly it is 
not a Cirrus , (Mons. Agassiz proposes to name it Cirrus Sow - 
erby ) ; Venus to Cyprina ; Mur ex 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. 
