200 Rhodora [OCTOBER 
mented with purple, the leaves are distant and pale green, and the 
leaf-cells are thin-walled throughout. In L. Mildeana, on the other 
hand, the plants are often tufted and grow on moist sandy soil as well 
as among Sphagnum, the stems are pale green, the leaves are fre- 
quently crowded and pigmented with purple, and the leaf-cells, 
especially in exposed localities, have their walls more or less thickened. 
In gemmiparous forms of L. Mildeana the stems are delicate and 
usually bear scattered leaves without any sign of pigmentation. 
Under such conditions the characters of the species are not clearly 
shown. There is little danger, however, of confusing such plants 
with L. marchica and a careful search will often show more typical 
plants in the near vicinity. 
7. PEDINOPHYLLUM INTERRUPTUM (Nees) Pearson, Hep. British 
Isles 269. pl. 111. 1900. Jungermannia interrupta. Nees, Natur- 
geschichte der europ. Lebermoose 1: 165. 1833.  Plagiochila inter- 
rupta Dumort. Recueil d'Obs. sur les Jung. 15. 1835. P. macrostoma 
Sulliv. Muse. Alleg. 227. 1846.  Plagiochila (Pedinophyllum) pyr- 
enaica, var. interrupta Lindb. Not. Soc. F. et Fl. Fenn. 13: 307. 
1874.  Pedinophyllum pyrenaicum, var. interruptum Schiffn.; Engler 
& Prantl, Nat. Pflanzenfam. 1?: 89. 1893.  Plagiochila (?) lobata 
Kaalaas, Nyt Mag. f. Naturv. 33: 274. 1893. New England, 
W. Oakes. On dolomite rocks in a ravine; Brookfield, Connecticut 
(A. W. E.). The distribution of P. interruptum in North America is 
very incompletely known. It has been reported from Greenland, 
Labrador, Ohio, and from a few localities in Canada. It has a wide 
range in Europe, and Stephani notes its occurrence in Japan.! 
The genus Pedinophyllum is at present monotypic and was based 
by its author, Lindberg,? upon Plagiochila pyrenaica Spruce,’ a species 
which is now considered to be a peculiar form or variety of P. inter- 
rupta. Many subsequent writers have denied the validity of the 
genus and have continued to include P. interruptum among the 
species of Plagiochila. Spruce,‘ to be sure, suggested that Pedinophyl- 
lum might be considered a distinct subgenus under Plagiochila, 
admitting that P. interrupta. differed from typical Plagiochilae in 
several important respects. Stephani, however, does not grant it 
! Bull. de l'Herb. Boissier 5: 81. 1897. 
? Acta Soc. Sc. Fenn. 10: 504. 1875. 
3 Ann. & Mag. Nat. Hist. II. 4: 105. 1849. 
* Hep. Amaz. et And. 452. 1885. 
