Johnson — Is Archceopteris a Pteridosperm? 1 17 



generic name from Palteoptoris (already preoccupied by Greinitz for a 

 supposed tree-fern) to Aroliseopteris. Dawson recorded three species as true 

 Areliseopteris — A. Halliana Gcipp., A. JacJisoiii, Dwn., A. Rogcrsi, Dwn. The 

 illustrations of these three species are very incomplete (isolated |>innules only, 

 in the case of two of them) and no fertile pinnules are shown or mentioned. 

 There is, however, a figure of a Sp/wnopteris Hitchcocldaud, Dwn. (op. cit., 

 PI. 15, fig. 175), which Dawson thinks may be tlie fertile state of A.Ji-icksoni. 



In 1882 Sir J. W. Dawsou (14) published a further account of these 

 beds under the title " Tlie Fossil Plants of the Erian (Devonian) and Upper 

 Silurian Formations of Canada, Part 2."' In this report he gives an amended 

 diagnosis of Archaeopteris, and excludes from it such sterile species as 

 Cycloptevis ohtiim, Lesqx. and Cyclopteris [Flatyphylluni] Brownii, Dwn. 

 Arcficeopteris Jaclisoni, Dwn., is further described, and its fertile pinnae are 

 illustrated. A new species, -^4. Gaspiensia, Dwn., is made known, and 

 illustrations of the sterile and fertile pinnae are given. Its fertile pintise, as 

 shown in Dawson's figure, are not distinguishable from those of A. hibeiitica 

 or of other species, while its sterile state, especially that shown in his 

 fig. 14, PI. 23, suggests A. Roemeriana in its small, non-overlaijpiug, stalked 

 pinnules. 



Dawson states that A. Gaspiensis and A. Jacksoiii are so near each other 

 that it is not easy to distinguish tliem except when the fructificaiion is 

 pi-eserved. Judging from the figures, these are useless for establishing 

 specific distinctions, and on the whole they suggest that A. Gasjnensis and 

 A. Jacksoni are very near to, if not identical with, A. Roemeriana, Gopp. 

 Althougli it is thus difficult to decide from the descriptions, on the exact limits 

 of the various species, one most interesting fact was established as early as 

 1871, viz., that Archaeopteris flourished along the banks of estuaries and in 

 marshy ground in the Upper Devonian epoch on both sides of the Atlantic, 

 viz , in Ireland, iScotland, and other parts of Western Europe on the one 

 side, and in the United States and Canada on the other. 



Renault's illustrated account (1883) of Archaeopteris (15) shows that he 

 also regarded it as Hymeuophyllaceous (e.g., " Sores clavifornies bivalves "). 



In 1888 R. Kidston (16) published the results of his examination of the 

 Dublin specimens of A. hibemica. He showed that the frond was stipulate, 

 and decided that the sporangia had no keel as stated by Schimper, and no 

 Hymenophyllaceous features, but that they were exannulate and Marattia- 

 ceous. He concluded (at the time), "There does not remain the slightest 



' Members of the Society will te interested to know tLat Dr. A. II. Foord, i'.g.s., the Editor 

 and Librarian of the Society, is specially thanked in this publication by Sir J. W. Dawson for the 

 help he received from him in the collection of the Canadian specimens of Archaeopteris. 



