178 Reviews. — Prof Dana — On Paleozoic Botany. 



indications of Fucoids 1 occur even still earlier in the Primordial 

 rocks of Canada and the United States. 



At this early period, however, animal life was already represented 

 by at least four great sub-kingdoms of the Invertebrata, namely, 

 Protozoa, Eadiata, Mollusca, and Articulata. 



Among plants Acrogens are first represented in the Uppermost 

 Silurian near Ludlow, where fragmentary remains of seeds referred 

 to the Lycopodiacece, and cortical markings have been discovered; 

 whilst in the Upper Limstones of Graspe, Canada (Upper Silurian), 

 a small species of Lycopodiacece, described by Dr. Dawson under the 

 name of Psilophyton princeps, occurs ; and in the Ohio Limestone 

 remains of a Tree-fern ( Caulopteris) have been met with. 



Prof. Dana mentions, as amongst the earliest types of terrestrial 

 vegetation, a Yew, named by Dr. Dawson Prototaxites Logani, stems 

 of which have been met with measuring three feet in diameter. 

 (Dana, op. cit. p. 258.) 



But in a paper by Mr. Carruthers, F.E.S., 2 communicated to the 

 Royal Microscopical Society of London, the author points out that 

 the fossil in question had been described by Dr. Dawson under two 

 names, namely, Prototaxites Logani, and Nematoxylon crassum and 

 had been referred by Dawson to Taxinew from its microscopic 

 structure. Mr. Carruthers, however, shows that the fossil is not made 

 up of wood-cells, but entirely consists of cellular filaments of two 

 sizes, interwoven irregularly in a felted mass, and that its affinities 

 are with the cellular Cryptogams. Eeasons are given for placing it 

 among the filamentous Chlorosperms, and the name is changed into 

 Nematophycus Logani, Carr. 



" In the Hamilton Beds" (Middle Devonian), writes Prof. Dana, 

 " the evidences of verdure over the land are abundant." 



" The remains show that there were trees as well as smaller 

 plants ; that there were forests of moderate growth, and great 

 jungles over wide-spread marshes." "These terrestrial plants include 

 Lycopodiacece, Ferns, and Equisetacece, the three orders of Acrogens, 

 or higher Cryptogams, and also Chara, but no true mosses ; and with 

 these there were Gymnosperms or the lower Phanerogams." (op. cit. 

 p. 268.) 



"Europe and Britain have afforded, in addition to sea- weeds, 

 remains of plants mostly related in genera to those of the United 

 States ; so that the other continents besides America had their Ferns, 

 Lycopodiaceae, Calamites, and Conifers. Devonian plants have also 

 been reported from Queensland, Australia." (op. cit. p. 283.) 



In passing from the Devonian to the Carboniferous period no great 

 difference is observable in the plant-remains. As in the later, so in 

 the earlier, "there were Lycopods of the tribes of Zepidodendron, 

 and Sigillaria, and various Ferns, Conifers and Calamites." " The 



1 " Some of the fossils, formerly regarded as indications of plants, are now believed 

 to be worm-tracks or borings. But others show by their branching forms that they 

 are true Fucoids." Dana's Manual of Geology, Eevised Edition, 1874, p. 169. 



2 Monthly Microscopical Journ. vol. viii. Oct. 1872, pp. 160-172, pi. 31 and 32. 

 See also Geol. Mag. 1873, Vol. X. p. 462, " Review of Fossil Botany." 



