1904] Evans, — Notes on New England Hepaticae, — II 169 



layer are distinctly thinner. The sUff leaves spread widely from the 

 stem, so that even when close together they do not present the 

 appearance of being crowded. They are strongly complicate and 

 are bifid about one-eighth with a short and blunt apical sinus and 

 broad and rounded lobes. The leaf-cells are usually distinctly 

 thickened throughout and have conspicuous trigones. The true M. 

 emarginata is a smaller plant with shorter and more delicate stems, 

 although the latter are essentially the same in structure. The leaves, 

 which spread more obliquely from the stem, are more obtusely com- 

 plicate and more deeply lobed, the lobes being sometimes blunt but 

 usually obtusely pointed. The walls of the leaf-cells are less strongly 

 thickened although still provided with conspicuous trigones. With 

 respect to color M. emarginata varies from bright green to reddish. 

 M. aqiiatica also varies considerably but is usually of a duller hue ; 

 sometimes it glistens as if varnished. Neither species ever exhibits 

 the deep purplish black color which is so often to be seen in M. 

 media. M. aquatica is apparently confined to alpine or subalpine 

 regions while M. emarginata descends into the plains. 



M. sphacelata attains its most characteristic development in the 

 boggy pools and sluggish brooks of subalpine regions. The follow- 

 ing are the only New England stations to be cited at present with 

 certainty : Mt. Washington, New Hampshire {D. C. Eaton, W. G. 

 Far/ow, A. W. E.) ; Mt. Mansfield, Vermont {D. C. Eaton, A. W. 

 E.). The records for Maine and Connecticut, therefore, in the 

 writer's Preliminary List of New England Hepaticae^ should be 

 revised. The species grows in broad thick tufts of a dull green 

 color often tinged with blackish and is much less firm in consistency 

 than the two plants Just considered. In cross-section the stem 

 shows a distinct border of large thin-walled cells; just within this 

 the cells have slightly thickened walls but pass gradually into the 

 thin-walled cells of the interior. The leaves are divided by a narrow 

 sinus into two broad and rounded lobes ; they are very delicate in 

 texture, and yet their cells, although thin-walled, show small but dis- 

 tmct trigones. M. media is found not only in the mountains but also 

 in the plains, and its range extends as far south as Georgia. It is a 

 much firmer plant than M. sphacelata and is usually much more 

 richly colored ; a deep purplish black is perhaps the most character- 



1 Rhodora, 5 : 170-173. 1903. 



