Nova Acta Academie Nature Curiosorum. 487 
appendix. The Calymene? equalis is from the same locality: it most 
nearly resembles the Calymene concinna, Dalm., and, like it, approaches 
very closely to the genus Asaphus. It is figured in the accompanying 
plate. 
The second section of the memoir is devoted to an essay ‘“* On the 
Mastodon Arvernensis of Eppelsheim.”” Of this species, which was 
unknown to Cuvier, and first described by MM. Croizet and Jobert, 
portions, consisting of the left half of the upper jaw and some isolated 
molar teeth, exist in the Museum of the Grand Duke of Hesse Darm- 
stadt. They were found at Eppelsheim, near Alzei, in the Grand 
Duchy; and are more worthy of notice as they fill up some deficiencies 
in the account of the skeleton which the first describers were compelled, 
from the incompleteness of their materials, to leave open to subsequent 
investigation. The whole of the materials are described at length, and 
the differences existing between them and the corresponding parts of 
Mast. maximus and angustidens are carefully noted. It appears that, 
in addition to the Auvergnian and Hessian habitats, the species is found 
in the Jura formation at Salmandingen and on the Heuberg; and also 
at Friedrichsgemiind in Bavaria, In the last named locality it occurs in 
a heliciferous limestone in company with remains of Mastodon angus- 
tidens, Paleotherium Aurelianense, Rhinoceros incisivus, Cheropota- 
mus Semmeringii, a Lophiodon, a small carnivorous animal, a Cervus, 
Tortoises, and other terrestrial quadrupeds; with regard to which, and 
to the tertiary formation in which tbey are found, Dr. Meyer states that 
he is preparing a separate memoir. The plate represents the Eppelsheim 
fragment of the upper jaw. 
“ The genus Aptychus,’’ Mey., (which is synonymous with Trigonel- 
lites, Park., Tellinites, Schloth., Icthyosiagones, Bourd., and Lepadites, 
Germ..,) is the subject of the following section. These paradoxical fossils, 
although known and figured so early as the time of Scheuchzer, and 
examined and described by many subsequent oryctologists, have hitherto, 
according to our authour, been completely misapprehended, as regards 
their affinities and classification. To the hypothesis that they are the 
remains of bivalve shells, which at first sight they closely resemble, he 
