30 Rhodora [February 



Arnica. In Eastern North America this genus lias one representa- 

 tive very nearly confined to the coastal plain (barely reaching the 

 Piedmont region in extreme southeastern Pennsylvania, and ranging 

 from there southward to Florida), while the others seem to be con- 

 fined to the glaciated region.^ 



If botanists residing near the terminal moraine and the fall-line 

 will bear these plants in mind hereafter, they can doubtless furnish 

 us with some interesting notes on their local distribution, and at the 

 same time discover other cases of the same kind. 



The following papers should be added to the bibliography of the 



subject. 



Adams, Chas. C. The postglacial dispersal of the North American 

 biota. Hiol. Hull. <):5,3 71. 1905. 

 Contains references to some earlier papers by the same author 



whicli should also be consulted. 



Beal, W. J. Michigan Flora. 147 pp. Lansing, 1904. 



HARSHUKHtiEii, J. W. The comparative age of the different floristic 

 elements of Eastern North America. Proc. Acad. Nat. Sci. Phila. 

 56:601-015. 1004. 



HOLLICK, AiiTiHTR. Notes on Block Islaiul [R. I.]. -Ann. N. Y. 

 Acad. Sci. llio.VSS. 1S9S. 

 Pages 00-70 contain an interesting discussion of the origin of the 



flora. 



MiEivSi'AUGii, C. F. Preliminary catalogue of the flora of West Vir- 

 ginia. Hull. W. Va. Agric. Exp. Sta. 2: 315 53S. 1S92. 



PouTEit, T. C. Flora of Peimsylvania. 302 pp. and map. 1903. 

 In this work the distribution of each species is given in (k^tail, by 



counties, and it is readily seen that the coastal plain element of the 



flora is very nearly conflned to the northeastern (piart(>r of the state, 



which is glaciated. 



University, Ala. 



'See Fernald, Rhodoka 7: 146. 1905. 



