434 PALEOBOTANY. 



which has the same carbonaceous texture as the plant to 

 which it is attached. Besides the above-mentioned ancient 

 types, we meet with fossil Fungi in almost all the succeed- 

 ing great formations, and in the Tertiary period they become 

 comparatively numerous, many forms occurring in amber.^ 



Lichens (Lichcncs), so far as known, are a modern group 

 of Cryptogams, their first recorded appearance being in 

 the Miocene Tertiary ; and the Pillworts {Rhizocaiyccc) are 

 hardly more ancient, as they are not known to occur in 

 deposits older than the Eocene. 



The three remaining groups of the Cryptogams — namely, 

 the Ferns (Filiccs), the Horse-tails (Bquisctaccai), and the Club- 

 mosses {Zycojjodiacccv) — all have their beginnings deep down 

 in the Paheozoic period. Ferns seem, according to recent 

 discoveries, to occur at least as early as the middle of the 

 Silurian period {Eopteris Andcgavcnsis) , and numerous forms, 

 differing in no essential points from those now in existence, 

 were differentiated in the Devonian period. The Equisdacew 

 are known from Devonian strata, though these ancient types 

 differ in important particulars from the living Horse-tails. 

 Lastly, the Lycopodiaccce appear to begin in the Upper Silu- 

 rian, with the curious Palaeozoic group of the Lepidodendroids. 



Coming next to the Phanerogams, we find that the group 

 of the Gymnosperms has a decidedly higher antiquity than 

 the Angiosperms (amongst the Dicotyledons), while the latter 

 are a much more modern type than the Monocotyledons. 

 Thus, the Conifers commence in undoulited forms as early 

 as the Devonian ; while the Sigillarioids (variously regarded 

 as Cryptogams, or as an ancient type intermediate between 

 Conifers and Cycads) seem to appear as early as the Lower 

 Silurian, The Cycads are doubtfully indicated as occurring 

 in Paheozoic strata, but are represented by unquestionable 

 forms in the Trias. The Angiospermous Dicotyledons, with 



^ Amber is a resinous exudation from the root-stock, bark, and wood of the 

 Miocene Pinites succinifer, and probably of other sjiecies, more or less related 

 to living Conifers. The masses of amber are casts of cavities in the lower 

 part of the stem or root. Amber thus closely resembles the modern "copal " 

 in nature and origin ; and its palseontological importance comes from the fact 

 that, besides the remains of plants, it contains an immense number of Insects, 

 Spiders, &c., in a beautiful state of preservation. 



