Page:VCH Norfolk 1.djvu/97

 BOTANY same year ; this, however, was decidedly nearer to F. hygrometrica, though presenting certain characters indicating an approach to the rarer species. It is interesting in the taxonomic study of mosses to find two forms so clearly uniting such apparently well-marked species as F. hygrometrica and F. microstoma. Another rare plant, gathered by Mr. Holmes in a bog near Holt, is Philonotis ccespitosa, Wils., a species (or sub-species) which differs from P. fontana mainly in having the bracts of the male inflorescence acute instead of obtuse and rounded. The inflorescence is rarely produced, but was present in Mr, Holmes' plant, and showed the bracts very markedly tapering and acute, much more so than in Wilson's own specimens. The specimen is therefore of special interest, as tending to support the view, held by some continental writers, that P. caspitosa is one of a series of intergrading forms connecting P. fontana and P. marchica, the latter a species not at present recorded from Britain. Some reference should be made to what is known of the mosses that occur in the county in the plant deposits of prehistoric times. The structure of the Cellular Cryptogams renders them peculiarly liable to destruction as compared with the higher Vascular plants ; hence they are scarcely found in the earlier formations, or indeed so far back as Tertiary times ; and even as regards the later deposits very little has been done towards identifying these lower plants, of which however there must be considerable remains in some of the Plant Beds in which East Anglia is rich. So long ago as 1872 Nathorst detected in the Arctic bed at Mundesley a single moss, Hypnum turgescens, Schpr. ; a very interesting discovery since that species does not occur at the present day in Britain, though distributed sparingly throughout central and arctic Europe, Quite recently the writer has had the opportunity of examin- ing some material from the same Arctic or Early Glacial beds at Mundesley, which contained considerable remains of this species, and of several others, some of great interest. Among these was a mere frag- ment of what appears to be undoubtedly Hypnum capillifolium, Warnst., a rare moss, found in scattered localities throughout the temperate zone of the northern hemisphere in both the old and new worlds, but not recorded hitherto from Great Britain. A third species, Hypnum Richard- soni. Mitt. {H. Breidleri, Jur.), is also of special interest, as with a some- what similar distribution to that of the two foregoing species it does not exist in Britain at the present day. It seems probable that further study of the mosses of these Plant Beds of Glacial times may add something to our knowledge of the origin and relationships of our island flora. LIST OF SOME OF THE RARER SPECIES AND VARIETIES The greater number of the Sphagna or peat-mosses recently collected have been submitted to Mr. E. Ch. Horrell, who has named them in accordance with the most recent views as represented by Warnstorf, and as this is a somewhat new departure I give the list in extenso. I 65 ^