92 
POPULAR SCIENCE REVIEW. 
BRITISH LAND AND FRESH- WATER MOLLUSKS* 
UCIT more has been done on the other side of the Channel toward 
clearing up the history of the above-named animals than has been 
accomplished in the British Isles. For even though the characteristically- 
speculative labours of Edward Forbes threw a good deal of light upon the 
distribution of these beings, still English concliologists were far behind 
their Gallic neighbours in this respect ; and we have had no work in our 
language which could in any way be compared with the diffuse and able 
researches of M. Moquin-Tandon as published in his “ Mollusques 
Terrestres et Fluviatiles.” The gap which so long existed has now been 
filled, and in filling it Mr. Lovell Reeve has brought the whole weight of 
his extensive concliological researches to bear upon the subject. Need we 
say, that he has produced a volume which is creditable to him in his 
double capacity of naturalist and publisher? We think not. One hundred 
and twenty-eight species have been described, and in every instance the 
descriptions are so ample and lucid that the merest tyro in molluscan 
zoology can find the identification of a specimen a matter of very little 
difficulty indeed. An exquisitely-finished engraving of the typical animal 
of each genus is intercalated with the text, and smaller woodcuts of the 
shells or animals accompany the several descriptions of the species. The 
lists of synonyms are copious and carefully prepared, and the habits of 
each species have been by no means neglected. The portion of the work, 
however, to which we would direct especial attention is that which refers 
to the distribution of specific forms ; this is incontestably the most valuable 
in a philosophic point of view, and it is to it that those endeavouring to 
solve the great problem of the origin of species will look for information. 
No pains have been spared by the author to render this branch of his 
subject as explicit as possible, and throughout the pages will be found 
admirably-drawn-out schemes explanatory of the geographical ranges of the 
various species. Taking Helix nemoralis as an illustration of how Mr. 
Reeve has advanced our knowledge of terrestrial mollusks, it will be 
observed that a scientifically-accurate description of the shell is first given, 
then that a list of fifteen synonyms, with dates, the habitat, and more than 
half a page of general description follow, and finally that the distribution 
is thus described : — “ II. nemoralis inhabits Europe throughout, but it is 
less common in the South. It has been transported to the United States, 
and keeps to the eastern parts near the sea, especially the lower extremity 
of Cape Codd and Cape Ann. Mr. Binney remarks, that in the neighbour- 
ing islands ‘each island is inhabited by a variety peculiar to itself, showing 
that the variety which happened to be introduced there has propagated 
itself without a tendency to run into other variations.’ Thus, on one island 
* “The Land and Fresh-Water Mollusks indigenous to, or natu- 
ralized in, the British Isles.” By Lovell Reeve, F.L.S. London : 
Reeve & Co. 18G3. 
