54 ON THE LAND AND FEESH-WATER 



Woodward, the Atlantic region, includes the New England 

 states, and all of the more southern states east of the Allegha- 

 nies. These mountains appear to divide two well marked 

 groups of land and fresh water-shells. Corresponding perhaps 

 with this zoological province, is the region of Asters and Soliclagos, 

 of Prof. Schouw. The difficulty is to separate the flora of the 

 region east of the Alleghanies from that to the westward of those 

 mountains. For although the fresh-water shells, of Pennsyl- 

 vania, for instance, have a distinct general aspect from those 

 of the state of Ohio, yet the plants of the two states are puzz- 

 lingly alike. That is to say, if we try to instance any group 

 of plants, (neither mountainous and probably sub-arctic species, 

 on the one hand, or species naturalized from Europe on the 

 other,) we shall find it very difficult to give a list of species 

 that do not inhabit both sides of the Alleghanies. Yet such 

 plants as Magnolia glauca, Spiraea tomentosa, Tillcea simplex, 

 Gnaphalium decurrens, Kalmia latifolia, Azalea viscosa, with sev- 

 eral species of Aster, Solidago, Nabalus (?), and Vaccinium, may 

 be considered perhaps as constituting a fair example of the Atlan- 

 tic flora. Prof. Schouw's region is described as being character- 

 ized by the paucity of Cruciferse, and Umbelliferas, by an almost 

 total absence of true heaths, which are represented by Vaccinium, 

 and Gaylussacia ; and by the abundance of Asters and Solidagos. 

 This province has not, been well defined from a geographical point 

 of view. On the supposition that the Atlantic region, as defined 

 geographically by Mr. Woodward, corresponds with Prof. Schouw's 

 botanical province, I think we may see that in its fauna and flora> 

 part of the Canadian area has affinities with this general natural- 

 history region. 



Almost all our Lower Canadian land and fresh-water shells are 

 found in the Atlantic states, north of Cape Hatteras. The same is 

 the case in Upper Canada, so far as we know, with the exception of 

 the southwestern peninsula of that province, as previously defined. 

 It is true, that some small fresh-water bivalves, of the family Cycla- 

 didse, have been described from the neighborhood of Lake Superior, 

 which have not yet been found anywhere else ; but these most likely 

 came from the south shore of the lake, in the state of Michigan, 

 and probably belong to the western natural-history region. la 

 Lower Canada, again, many species of Solidago and Aster abound ; 

 the genus Erica appears to be wholly absent, several species of 

 Vaccinium and a Gaylussacia (G. resinosa) appearing instead, 



