4 Rhodora [JANUARY 
soon became accepted by European writers, and R. bifurca is now 
recognized as a definite species throughout northern Europe. Whether 
or not the course pursued by Heeg was justifiable is a question. It 
would probably have been better if he had given up the name R. 
bifurca altogether and had chosen a new name fer the species. At any 
rate it must be admitted that the present definition of R. bifurca is 
Heeg’s and that it is very doubtful whether his conception of the 
species would agree with Hoffmann’s or even with Lindenberg’s. 
In case it should be proved beyond question that R. arvensis and 
Heeg’s R. bifurca were identical, the writer suggests that the species 
should bear the name given it by Austin. 
One of the closest allies of R. arvensis is apparently R. glauca L., 
a common European species which is known in North America from 
California only. This species is perhaps to be expected in the eastern 
United States. Its thallus differs from that of R. arvensis in having 
sharper margins and in being relatively thinner, the thickness being 
only one fourth as great as the width or even less. The spores of 
R. glauca are much like those of R. arvensis, except that the meshes 
of the convex face average a little larger. 
2. Riccra Austini Steph., Bull. de l'Herb. Boissier 6: 336. 1898. 
R. lamellosa Aust., Hep. Bor.-Amer. 140. 1873 (not Raddi). R. 
lamellosa, var. americana M. A. Howe, Bull. Torrey Club 25: 189. 
1898 (in part). On moist black earth in paths among rocks, some- 
times in company with R. Lescuriana and R. sorocarpa. West Rock 
Ridge, Connecticut; first discovered in the town of New Haven (G. E. 
Nichols, 1911) and afterwards in the town of Woodbridge (A. W. E.). 
Since collected on South Mountain, Meriden, Connecticut (Miss 
Lorenz). The species was based on material collected by Austin 
near Closter, New Jersey, and issued as R. lamellosa. Its geographi- 
cal distribution is very incompletely known. Underwood ! reported 
R. lamellosa from Ontario, Alabama, and California, as well as from 
New Jersey, and the same species is listed without definite stations in 
Bennett’s Plants of Rhode Island. The Californian material in the 
Underwood herbarium has since been described by Howe? as a dis- 
tinct species under the name R. americana, but it is probable that 
some of the eastern specimens would now be referred to R. Austini. 
Unfortunately the question cannot be answered at the present time. 
1 Bot. Gaz. 19: 278. 1894. 
2 Mem. Torrey Club 7: 24. pl. 90. 1899. 
