134 
long time and is easily renewed. The whole adjustment 
costs but a few cents, and may be constructed by any one. The 
carbon here exhibited has been under acid for more than two 
months. This device may have been already in use, for 
aught I know; butI have found it so convenient, that I have 
thought it not amiss to present it, 
April 20th. Geological Section. 
PRESIDENT NEWBERRY in the chair. Twenty persons present. 
Among the books received at this meeting, was the “ Cata- 
logue of Air-breathing Vertebrates from the Coal-measures of 
Linton, Ohio ;” by Prof. E. D. Cope, in reference to which,— 
THE PRESIDENT gave a description of the Linton coal-bed, 
and of its remarkable fauna. The locality had evidently 
been a lagoon or sheltered bay on the shore, quiet and se- 
cluded, but opening into the sea, as is shown by the numer- 
ous teeth and spines of sharks. In this lagoon there had 
formed a thick deposit of carbonaceous mud, now hardened 
into a seam of cannel coal, in which are imbedded the 
remains of some twenty-five species of ganoid fishes, Coelacan- 
thus, Eurylepis, Rhizodus, ete., and also of an equal number 
of species of amphibians, as now described by Prof. Cope. 
This number exceeds that of all the Carboniferous amphibi- 
ans previously known to science; and we have here a sug- 
gestive glimpse of the abundance, in that period, of vertebrate 
life, of which, at most points, so little is preserved tous. A 
locality of similar richness is that at Mazon Creek, Illinois, 
which has likewise yielded a number of interesting species. 
These batrachians, many of which are closely related to such 
forms as Menobranchus, now living in our western rivers and 
lakes, flourished in this old lagoon at Linton, and found 
abundant sustenance in the swarms of ganoid fish, the spines, 
scales, and teeth of which fairly fill the cannel. Some of 
them were quite large, attaining a length of several feet. 
This seam of cannel was formed from a washed and mace- 
rated mass, composed of the soft parts of the vegetation of 
the coal-marsh into which the lagoon or inlet extended. It 
