R. P. Whitfield—Carboniferous air-breathing Mollusk. 125 
Art. XV.—Notice of a new Genus and Species of Air-breath- 
ing Mollusk from the Coal-measures of Ohio, and Observations 
on DAWSONELLA; by R. P. WHITFIELD. 
possessed up to that time of the shells of this group of mollusks 
occurring in these formations. The recognition and descrip- 
oO what is supposed to be a similar form from the 
Devonian formations of New Brunswick adds a feature of great 
already so admirably done for me. 
The form from Ohio is so entirely distinct from any and all 
of those previously described, although, like them, of minute 
size, that I have concluded to call immediate attention to it. 
pore-like notch occurring near the upper angle of the aperture 
ma Vi 1 lus 
least not in the same degree nor with the same apparent pur- 
considered it entitled to rank as the type of a distinct genus, 
