REVIEWS. 
417 
The decade by Professor McCoy is a continuation of the description of 
the characteristic Victorian organic remains, and contains a number of illus- 
trations of the fossils of the tertiary formations, and some other forms 
interesting to the geologist. Among these is much additional information 
as to the characters and dentition of the singular animal, the marsupial lion 
of Owen, and illustrations of some new tertiary species of Cyprcea , Aturia, 
Pleurotomarici, and Trigonia, the latter two genera abounding in the mesozoic 
rocks, but of excessive rarity in recent and tertiary times, so that the species 
here described form an interesting addition to the history of the distribution 
of these genera in time and space. Some species of trilobites are also figured 
which are absolutely identical with forms abounding in the upper Silurian 
rocks of Europe — one of them British, and the other common in the Silurian 
basin of Bohemia — showing the wide range of similar species of trilobites, 
like those of graptolites described by Prof. McCoy in a previous decade in 
the seas of the palaeozoic period. 
THE SHELL MOUNDS OF FLORIDA.* 
T HIS memoir by the late Professor J. Wyman relates almost exclusively 
to the shell mounds and shell fields on the banks of the St. John’s 
River in East Florida, which, as far as at present known, were the dwell- 
ing-places of the earliest inhabitants of the region through which this river 
flows. But little is known of the origin of these antiquities, which were 
long considered to be of natural and not of artificial origin. These mounds 
consist entirely of certain species of Unio, Ampullnria, and Faludina, of 
which the latter forms the largest portion of every mound, and with a 
few Unios the whole of some. Sometimes one species forms considerable 
deposits by themselves without the admixture of the others, as if at certain 
times they had been exclusively used as food ; occasionally other shells, as 
Melanise and Helices are found, but in very small numbers. The mounds of 
St. John’s appear to differ from the shell mounds of other rivers of the 
United States, which latter consist almost exclusively of Unios, those of St. 
John’s being peculiar as affording the only, or at least the chief, instances in 
which the Ampullarias and Paludinas have become to so large an extent 
articles of food. They are also different as to their characteristics from the 
mounds on the sea-coast, which are composed entirely of marine species of 
shells. 
These mounds are almost in all cases built close along the banks of the 
river, usually in the form of long ridges parallel to the shore, rising some- 
times to the height of twenty feet or more, and resting either on ridges of 
sand or river mud, or on land slightly raised. They are often placed at the 
union of the river with a lagoon or creek, or at the outlet of a lake, such 
places probably giving the natives ready access in canoes to large areas for 
* “Freshwater Shell Mounds of the St. John’s River, Florida.” By. J. 
Wyman, Peabody Academy of Science. Fourth Memoir. Salem, Mass. 
1875. 
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VOL. XV.— NO. XLI. 
