y 



i 



1863.] . ' DAWSON — -DEVONIAN PLANTS. 463 



ties of C. JacJcsoni and of C. Halliana in PI. XIX. figs. 26 & 28. I 

 may add here that the stipe of Cyclopteris Jacksoni has a few leaves 

 between the pinnules of the upper part, but is less leafy than that 

 of (7, Halliana. 



12. Cyclopteris Rogersi, spec, nov. PI. XVII. figs. 17, 18; and 

 PL XIX. fig. 27. 



Habit of growth resembling that of Cyclopteris Jacksoni, but the pin- 

 nules are more elongated and almost cuneate in form, also less 

 densely placed, and with veins more nearly parallel. Stipe stout, 

 woody, furrowed longitudinally, and marked with strong transverse 

 bars or punctures. 



This Fern is less abundant than C. JacJcsoni, from which the points 

 above mentioned appear sufficient to distinguish it. Its stipe is 

 marked in the manner of Rhachiopteris punctata of the Chemung 

 group of New York, and of 0. Roemeriana, Goeppert, from the 

 Upper Devonian of Europe ; of the latter species the present may 

 be regarded as the American representative. I have endeavoured, 

 from the small fragments collected, to give characteristic repre- 

 sentations of the appearance of the species. It was probably about 

 the same size as C. Jacksoni, but with its stipe not leafy, and its 

 pinnae and pinnules less densely placed. 



It would seem that the remarkable group of pinnate Cyclopterides, 

 to which this species belongs, was characteristic of the Upper De- 

 vonian throughout North America and Europe. I dedicate the pre- 

 sent member of it to Prof. W. B. Rogers, who has done much to 

 direct attention to the deposits of Perry, and has kindly permitted 

 me to use the specimens in his collection. 



13. Cyclopteris Brownii, Dawson. PI. XVII. fig. 6. 



This fine species, described in my former paper from a mere frag- 

 ment of a frond, I am now able to figure in its full dimensions, from 

 a fine specimen in the collection of Prof. Rogers of Boston ; several 

 others, nearly as perfect, were found by Mr. Brown and myself last 

 summer. It has a large simple frond, nabellate in form and divided 

 toward the edges, which are sometimes slightly reflected, as if they 

 had borne marginal fructification. It belongs to the group of sim- 

 ple-leaved Cyclopterides, like C. orbicularis, Brongn., of the Coal- 

 measures, or 0. digitata and C. Huttoni of the Oolite. It very 

 closely resembles a beautiful leaf from the Ponent (Upper Devonian) 

 of Pennsylvania, figured, but not named, by Prof. H. D. Rogers in 

 his Report on the Geology of that State (vol. ii. pt. 2. pi. 22). This 

 resemblance did not appear from my imperfect specimen of last year ; 

 but I can'scarcely now doubt that Prof. Rogers's Plant is the same, 

 or very closely allied. The leaf from Pennsylvania was compared 

 by Prof. Balfour, to whom it was submitted by Prof. Rogers, with 

 that of Salisburyia adiantifolia, to which it unquestionably bears a 

 strong resemblance ; and it may admit of doubt whether it is really 

 a Fern or a coniferous leaf. In the absence of fructification it may 

 be impossible to decide this question j but the form and texture of 



