Bd. III; 14) 
THE MESOZOIC FLORA. 
3 
With the exception of the small coniferous fragment from Snow Hill Island, all 
the species described in the present paper are from one and the same series of 
rocks at Hope Bay, on the west side of Antarctic Sound. The geology of this 
region has been described by J. G. Andersson (1906, p. 24 and following) and 
need not be dwelt upon here. The plant-remains have all been found in a hard, 
dark slaty rock which forms the lower part of Mount Flora and is capped by a 
series of volcanic tuffs. In close connection with the slate is a “dark tuff or tuffoid 
conglomerate with pieces of carbonized wood” (|. G. Andersson, 1 . c., p. 26). 
The whole series contains no marine fossils which could serve as a basis for the 
determination of the age of the plant-bearing rocks. Some very badly preserved 
bivalves have been found together with the plants, but they have not yet been 
e.xamined by a specialist. They seem, however, according to J. G. ANDERSSON 
( 1 . c., p. 27), to be a freshwater form. On account of this fact and some peculiari- 
ties of the flora, to be mentioned below', the plant-bearing beds are considered a 
lacustrine deposit. The only available information on the geological age ot the series 
is, under these circumstances, afforded by the flora itself; and the latter has been, 
in the preliminary publications, assigned to the Upper Jurassic. 
The plant-bearing series has been involved in the folding of the Antarctic 
Andes. The dark slaty rock containing the plant-remains is very hard and partly 
laminated and shows evident traces of pressure. This metamorphic nature of the 
rock, though not very marked, is probably to some extent responsible for the rather 
unsatisfactory state of preservation of the fossils. The organic substance of the 
plants has entirely disappeared or has been replaced by some mineral matter which 
retains no trace of the original structure. Nor are there in the slate any carbona- 
ceous remains of wood or other parts of the plants. The impressions differ very 
little in colour from the dark matrix and are altogether unsuitable for photographic 
reproduction. A great drawback is also caused by the fact that the finer details of 
the venation are often obliterated. The outward shape, however, is well preserved; 
and many of the plant-remains attain considerable dimensions. 
In the classification of the plant-remains, I have acted on the conviction that it 
is a lesser evil to keep forms separated which are identical than to identify such as 
are distinct. There can be no doubt that from both a systematic and a phyto-geo- 
graphical standpoint, this principle is the one to be preferred. It is true that it is 
looked upon by many as rather a cause of confusion in palæobotanical nomenclature 
because it involves the creation of many new names which are only to be rejected 
later. The fact that a great number of synonyms may ultimately have to be recorded 
under each of the more widely distributed or polymorphic species need not, how- 
