GOG Contributions to Invertebrate Palaeontology. 



PULMONIFERA. 



The existence of shells of terrestrial air-breathing- Mollusca in 

 the Coal Measures of this country was first made known in the 

 year 1851, when Sir Charles Lyell and Prof. J. W. Dawson made 

 known their discovery of Pupa vefusta in the coal-beds of the South 

 Joggins, Nova Scotia. Since that time there have been several 

 additional species discovered in the same region, and others in the 

 Coal Measures of Indiana. In the Am. Jour. Sci. for November, 

 1880, Prof. Dawson has given a summary of the species known 

 from the coal formations up to that time, and also described what 

 he supposes to be a similar form from the Devonian plant-beds of 

 St. John, New Brunswick. At the time Prof. Dawson's memoir 

 appeared I was working on the form herein described, from the 

 Upper Coal Measures at Marietta, Ohio, which has proved to be so 

 entirely distinct from any of those previously known that it became 

 necessary to found a new genus (Anthracopvpa) for its reception, 

 which was published in the above-mentioned journal, February, 

 1881. 



All the species knoAvn up to the time of Prof. Dawson's paper 

 were supposed to belong to the inoperculate division of the terres- 

 trial Gasteropods, and had been referred to the Helicid^ and 

 PuPiNiE. In making the studies of the Ohio shell I had obtained, 

 through the kindness of John Collette, Esq., State Geologist of 

 Indiana, specimens of the two forms from that State, and in freeing 

 them from the matrix I discovered that the species Dawsonella 

 Meeki Brad, possessed not only the reflected and slightly thickened 

 lip described by its author, but that the inner lip and much of the 

 umbilical region were covered by a thickened and flattened callus 

 closely resembling that of Helicina, furnishing strong presumptive 

 evidence that it had been provided with an operculum, like those of 

 that genus. If this view of its nature is correct, it would place it 

 with the HELTCTNiDiE in the operculate section of the Pulmonifera. 

 The Ohio shell has also some peculiar features that are not recog- 

 nized among any of the Pupa-form species heretofore described from 

 this formation. It is of small size, and the general form is similar 

 to that of the group of the Pupae usually referred to the genus 

 Vertigo; minute' shells with a nearly vertical aperture, armed with 

 several projecting tooth-like points within its cavity. This shell 



