184 BOTANICAL GAZETTE. [July, 



discovery. After carefully studying the available material it was pub- 

 lished by Dawson under the name of Prototaxites Logani with the follow- 

 ing diagnosis : " Woody and branching trunks, with concentric rings of 

 growth and medullary rays; cells of pleurenchyma not in regular lines, 

 cylindrical, thick- walled, with a double series of spiral fibers; disks or 

 bordered pores few, circular and indistinct. The specimens are usually 

 silicified, with the bark in a coaly state." Although Dawson states in the 

 notes accompanying Prof. Penhal low's paper that he did not intend to 

 imply its coniferous nature, the fact that it was named Prototaxites, and 

 compared with the Aporoxylon of Unger and with the wood of various 

 conifers, was taken to imply its taxine nature, and it was for a long time 

 regarded as one of the oldest ancestors of our modern conifers. 



Carruthers was the next to take up the subject. He obtained simi- 

 lar material from the Silurian of Wales, and concluded from its examin- 

 ation that it was the trunk or stem of a gigantic sea-weed. He therefore 

 named it Nematophycus. 



It was with a view of settling, if possible, the question of its affinities, 

 that the examination of Prof. Penhallow was undertaken, with the aid of 

 a more extensive and perfect series of specimens. His results, which 

 may be taken as final, fully confirm those of Carruthers. He says " that 

 it is an alga admits of no doubt ; and so far as the structure alone will 

 permit a final decision, its affinity with the Laminariaceje as first pointed 

 out by Mr. Carruthers, who therefore assigned it to the genus Nemato- 

 phycus, appears to be highly probable." 



Dawson has accepted their conclusions, and in his recently published 

 "Geological History of Plants " has modified the name to Nematophvton. 

 The original species becomes N. Logani, and Prof. Penhallow has de- 

 scribed a new species, N. laxum, from the lower Erian of Gaspe, which 

 with the Wales species, N. Hicksii, makes up the present known forms. 



Prof. Penhallow also describes some very peculiar laminated fossils 

 associated with Nematophyton Logani. They have the appearance of 

 being matted and crumpled masses apparently of fronds, and although 

 the structure is very badly preserved, are fairly comparable to the fronds 

 of the Laminariese. They may possibly have been the fronds of Nema- 

 tophyton, but this is merely conjecture, as they were not found in actual 

 contact.— F. H. K. 



Die fossilen Pflanzenreste. 9 



Paleobotany has passed beyond the stage in which the entire body of 

 its workers are devoting their energy to mere description of species, and 

 has entered upon broader, philosophical grounds. That this is true, is 

 shown by the publications of Williamson, Ettingshausen, Renault, Solms- 

 Laubach, and now by the admirable resume" by Dr. Schenk. It is, of 

 course, true that this broader view is only possi ble after the accumula- 



Botaniif E Rrl%v R ' r^J^ f £ ssi , len p fianzenreste. Sonderdruck aus dem Haudbuch der 

 uotanik, Hd. XV. Breslau, \ erlag von Edward Trewendt. 1888 



