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provided with a pore even at maturity, and the boundaries of the 
chambers remain distinct. In Grimaldia, however, many of the su- 
perficial air-spaces have no pores in the mature thallus and the boun- 
daries of the spaces are indefinite. 
4. Metzgeria dichotoma (Swartz) Nees. 
The remarkable gemmae of this species, characterized by the reg- 
ular presence of two apical cells, were recently described and figured 
by the writer from Porto Rican specimens collected by E. G. Britton 
and D. W. Marble on Mt. Morales, near Utuado (No. 498)} The 
determination of these specimens was considered at the time a little 
doubtful because no gemmiparous material from Jamaica, the type 
locality of M. dichotoma, had been available for comparison. During 
the past summer, however, through the kindness of Mr. A. Gepp, the 
writer was allowed to examine a number of Hepaticae in the herba- 
rium of the British Museum at South Kensington, and among these 
was a gemmiparous specimen of the species in question collected in 
Jamaica by Wilson (No. 817). Since the gemmae on this speci- 
men agree closely with those on the Porto Rican material the deter- 
mination of the latter as M. dichotoma may now be considered as defi- 
nitely established. 
5. Metzgeria FRUTicui OSA (Dicks.) Evans, Ann. Bot. 24 ; 
296. f. 16. 1910. 
In the writer’s recent account of this interesting species only one 
American locality could be quoted, namely : near Aberdeen, Wash- 
ington, A. S. F'oster (No. 944). In the herbarium of the British 
Museum a second American specimen is preserved, collected by W. 
Lobb in Oregon, no more definite description of the station being 
given. In all probability the species has a wide distribution in the 
United States and Canada. 
6. SCAPANIA SPlTZBERGENSIS (Lindb.) C. Mull. Frib. Bull. 
Herb. Boissier II. 1 ; 607. 1901. Nova Acta Acad. Caes. Leop. 
Carol. 83 ; 177. pi. 24. 1905. Martinellia spitz bergensis Lindb. 
Kongl. Sv. Vet. Akad. Handl. 23L; 31. 1889. 
Collected in 1896, on the Nugsuak Peninsula, Greenland, by the 
Cornell Party with the Peary Expedition. An arctic species, new to 
North America. Known also from Spitzbergen, the type locality, 
and from Siberia, The determination of the Greenland specimens 
has been confirmed by Muller. 5. spitzbergensis bears a superficial 
resemblance to large forms of 5. nemorosa (L.) Dumort., with which 
it was at first confused. Its leaves, however, differ in having strongly 
convex and reniform dorsal lobes and arched keels, each bearing a 
broad, spinose-dentate wing. In 5. nemorosa, the dorsal lobes are 
plane or slightly convex and broadly ovate in outline, while the keel 
1. Ann. Bot. 24 : 288. f. 13. 1910. 
