ISO EOYAL SOCIETY OF CANADA 



first subfauna; but the former is also found in tlie Upper Cordaite 

 shale east of St. Jolin Harbor. And here again the ecological question 

 comes up, for it is evident that these two forms were lovers of the 

 borders of shallow ponds occurring in hollows of the river-sands which 

 constituted the bulk of the Dadoxylon sandstone; they, no doubt, 

 existed elsewhere, under suitable conditions both earlier and later than 

 their growth on the border of these sand-enclosed pools. 



The varieties and mutations of other species noted in the above 

 descriptions are, no doubt, also due to an environment specially suitable 

 to the production of the differences noted. As instances of luxurious 

 growth imder favourable conditions one might refer to Annular ia lati- 

 folia, as compared with its earlier form A. longifolia-minor, and the 

 luxuriant whorls of Annularia longifolia — Leavitti as compared with 

 the ordinary later growths of this species as preserved in the Coal 

 Measures. 



It is an unexpected discovery to find such common species of the 

 Coal Measures as Calamités Cistii and Calamités Sucl-ovil flourish- 

 ing in full perfection at this early time in Geologic History. It shows 

 how much we have yet to learn respecting the first appearance and 

 distribution of the denizens of the land and the estuaries, botli animal 

 end vegetable, for if we have the identical plants of the Carboniferous 

 time in these plant-beds, why may we not have as well the land-snails, the 

 insects, the myriapods and the amphibians of Carboniferous type. 



