attuched to them, while Rhodea is merely a provisional genus 

 formed to include certain ferns of the Hymonophyllid group, but 

 otherwise of uncertain affinities. In the same not« M. Crepin 

 intimates that Mr. Carruthers has abandoned his Pnilophyton 

 Dcchenianum, published in the Journal of Botany for 1843, and 

 in which he had included Salter's Lepidodendron nothum and 

 fji/ropoditcH Milleri and " rootlets," as well as Goeppert's Ilali- 

 sirites Dechenidiius and a peculiar plant given to him by Sir P. 

 Egerton ! -^ Such a change of opinion I must admit to be judi- 

 cious. The fact that these plants could, even conjecturally, be 

 identified by a skilful botanist, shows however how imperfectly 

 they are known, and warrants some investigation of the causes 

 of this obscurity, and of the true nature of the plants. 



The characters given by Mr. Carruthers in his paper of 1873 

 for the species /'. Declienianuni, are very few and general: — 

 " Lower branches short and frc(juently branching, giving the 

 plant an oblong circumscription." Yet even these characters do 

 not apply, so far as known, to Miller's fucoids or Salter's rootlets 

 or Goeppert's ILdiseritex. They merely express the peculiar 

 mode of branching already referred to in Salter's Lepidodendron 

 nothum. The identification of the former plants with the Lepi- 

 dodendron and Lycopodites indeed rests only on mere juxtapo- 

 sition of fragments, and on the slight resemblance of the decorti- 

 cated ends of the I ;'anche^ of the latter plants to Psilophy ton. 

 It is contradicted by the obtuse ends of the branches of the 

 Lepidodendron and Lyco2)odifes, and by the apparently strobi- 

 laceous termination of some of them. 



Salter's description of his Lepidodendron is quite definite, and 

 accords with specimens placed in my hands by Mr. Peach : — 

 " Stems half an inch broad, t ipering little, branches short ; set 

 on at un acute angle, blunt at their terminations. Leaves in 

 seven to ten rows, very short, not a line long and rather spread- 

 ing than closely imbricate." These characters however, in so 



* Mr. (y'arrutheris has elsowhovo 'n\\iniifntd Lepidodendron not hum and 

 L. Guispianum with Leptoi>hlcuiii rhombicum, and this with an Austral- 

 ian species ooUectod by Mr. Daintreo in Queensland, but which I 

 subsequently found to be a sp(!cies allied to the well known Lepido- 

 dendron tetrciffoniim ot the Lower Carboniferous, and which had been 

 previously discovered by Mr. Solwyn in the Carboniferous of Victoria. 

 See Carruthers' paper in the Journal of the Geological Society, vol. 

 28, and my criticism in vol. 29, wh>''h last was however only printed 

 in abstract, and with some comments under the head of" Discussion," 

 to which if present I could have very easily replied. 



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