462 THE CANADIAN NATURALIST. [Vol. IX. 



If we exclude the alleged Palmorhis above referred to, all the 

 Paleozoic Pulmonifera hitherto found are American. Since, 

 however, in the Carboniferous age, Batrachians, Arachnidans, 

 Insects and Millipedes occur on both continents, it is not un- 

 likely that ere long European species of land snails will be 

 announced. The species hitherto found in eastern America, 

 are in every way strangely isolated. In the plant-beds of St. 

 John, about 9,000 feet in thickness, and in the Coal-formation 

 of the South Joggins, more than 7,000 feet in thickness, no 

 other Gasteropods occur, nor, I believe, do any occur in the beds 

 holding land snails in Illinois. Nor, as already stated, are any 

 of the aquatic Pulmonifera known in the Paleozoic. Thus, in 

 so far as at present known, these Paleozoic snails are separated 

 not only from any predecessors, if there were any, or successors, 

 but from any contemporary animals allied to them. 



It is probable that the land snails of the Erian or Carboni- 

 ferous were neither numerous nor important members of the 

 faunas of those periods. Had other species existed in any con- 

 siderable number, there is no reason why they should not have 

 been found in the erect trees, or in those shales which contain 

 land plants. More especially would the discovery of any larger 

 species, had they existed, been likely to have occurred. Further, 

 what we know of the vegetation of the Paleozoic Period would 

 lead us to infer that it did not abound in those succulent and 

 nutritious leaves and fruits which are most congenial to land 

 snails. It is to be observed, however, that we know little as yet 

 of the upland life of the Erian or Carboniferous. The animal 

 life of the drier parts of the low country is indeed as yet very 

 little known ; and but for the revelations, in this respect, of the 

 erect trees in one bed in the Coal-formation of Nova Scotia, our 

 koowledge of the land snails and millipedes, and also of an 

 eminently terrestrial group of reptiles, the Microsauria, would 

 have been much more imperfect than it is. We may hope for 

 still further revelations of this kind, and, in the mean time, it 

 would be premature to speculate as to the affinities of our little 

 group of land snails with animals either their contemporaries or 

 belonging to earlier or later formations, except to note the fact 

 of the little change of form or structure in this type of life in 

 that vast interval of time which separates the Erian Period from 

 the present day. 



