—86— 
of the cross section of the thallus, is not so in reality. Familler (3, p. 14) has 
shown that typical R. pseudo-Frostii, in some of his cultures, became directly 
transformed into R. Huebeneriana, and Nicholson (6, p. 202) has confirmed these 
results by careful observations in the field. There is every reason to suppose 
that R. fluitans is fully as variable as R. Huebeneriana. The so-called "broad 
form" of Von Gaisberg and the terrestrial form obtained by Donaghy in his 
study of the aquatic R. fluitans should therefore be subjected to a more rigid 
scrutiny than they have yet received, in order to determine whether their dis- 
tinctive features are constant or inconstant in character. Until this is done 
their status must remain uncertain. Renewed search should likewise be made for 
the aquatic form of R. fluitans in fruiting condition, in order to determine whether 
or not the marginal lobing of the Tempelhof specimens represents a constant 
feature and also to compare the spores with those of the terrestrial form. 
Yale University 
Literature cited 
1. Dona.ghy, F. The morphology of Riccia fluitans L. Proc. Indiana Acad. Sci. 1915: 13 1-13 j. 
1916. 
2. Familler, I. Die Lebermcose Bayerns. Eine Zusammenstellung der bisher bekanntgewordenen 
Standortsangaben. Denkschr. KgL Bayer. Bot. Ges. Regensburg 13: 153-305- 1917. 
3. Die Lebermoose Bayerns, zweiter (beschreibender) TeiL Denkschr. Bayer. Bot. Ges. 
Regensburg 14: 1-167. pi. 1-27 + /. 1920. 
4. Gaisberg, E. von.. Beitragezur KenntnisderLebermoosgattungi?«c«"a. Flora 114: 262-277. 
1921. 
5. Juel, O. Ueberden anatomischen Bau von Riccia Bischoffii Hub. Svensk Bot. Tidskr. 4: 160- 
166. pi. 7 +/. 1-5- 1910. 
6. Nicholson, E. New or rare British hepatics. Jour. Bot. 59: 202-204. 1921. 
7. Torka, V. Ricciella Hubeneriana (Lindenb.) N. v. E. Helio? 23: 105-107. 1906. 
8. Lebermoose aiis dem Nordosten der Provinz Posen. Hedwigia 50: 204-209. 1911. 
9. Bryotheca Posnanienbis 2. 1914- 
THE MOSSES OF THE OXFORD UNIVERSITY EXPEDITION TO 
SPITZBERGEN, 1921 ^ 
H. N. DiXON, M. A., F. L. S. 
The mosses sent to me for determination were collected by three of the botanists 
who took part in the expedi ion, in June — August, 192 1. Part of them were 
collected and sent to me by Mr. John Walton, and were collected about Klaas 
Billen Bay, mostly in the neighborhood ot Bruce City. The remainder were 
sent by Mr. V. S. Summerhayes and were mostly collected by himself in various 
localities (Bear Id., Prince Charles Foreland, &c.); but a certain number of them 
were gathered by Mr. C. S. Elton in the neighborhood of Klaas Billen Bay. 
The number of species found among these collections was about 82, out 
^ Constituting Number 17 of the Results of the Oxford University Expedition to Spitzbergen,i92l . 
