A 
a Silurian of a flora similar in type to that of the Lower 3 
-but probably richer in species. 
Group of New York and in the sandstones of St. John, 
102 REVIEWS AND BOOK NOTICES. 
Laurentian period. He thinks it “possible that the rocks of 
foundland or Labrador, or beds now buried under the Atl 
may be those which alone contain the remains of the lower Sil 
rian plants.” The Eophyton of Torell from the primord 
Lower Silurian rocks of Sweden, “if a land plant at all” 
Dawson regards “it as a doubtful plant, similar forms being 
ently produced by impressions of feet or fins on the surf: 
mud”), the author regards as more nearly allied to Psilop 
than to any other genus, saying that ‘‘ whatever the nati 
these forms, they are present in the primordial of America as 
Mr. Murray has found them in Newfoundland and Mr. Sel 
Nova Scotia, in rocks probably of this age.” 
“ Such views as to a primitive Silurian and Laurentian flora 
strengthened by the obvious fact that the plants of the lower 
middle Devonian have the aspect of the remains of a decay 
flora verging on extinction, and pointing backward in geol 
time, while those of the upper Devonian give us a great m 
of new forms and point onward to the Carboniferous. 
stated, the lower and middle Erian flora stands 
é mer 
trees, all having the structure of Prototaxites. In the H 
and thence to the modern Araucarian pines. There is n 
tion from one type to the other, nor are they intermixed 
same beds. The Middle Devonian would thus seem to nav 
the grave of Prototaxites, and the birth-place of Dadoxylon, 
far as the regions in question are concerned. a 
Something of the same kind occurs in the Carboniferous: 
scanty and somewhat antique Lower Carboniferous flora Pt 
backward to the Upper Devonian, just as the Lower we 
may be supposed to point backward to the Silurian. -y 
reasons lead me to anticipate with confidence the discov 
Is it possible to indicate where such earlier flora p ; 
pected? In Eastern America, from the Carboniferous A 
ward, the centre of plant distribution has been the API i 
