FLORA OP THE DEVONIAN. 549 



times dichotomous. This is one of the most perfect ami beautiful 

 of the St John Ferus. It resembles at first sight Sphenopteris 

 macilenta, L. and H. ; but on examination it diflfers materially in 

 details. It is an elaborate and ornate example of the peculiar type 

 of Cydopteris already referred to as characteristic of the Upper 

 Devonian Period. 



Cyclopteris varia, Dawson. Pinnate (or bipinnate). Pinn» with 

 a thick petiole. Pinnules decreasing in size to the terminal one, 

 which is ovate' and lobed. Pinnules oblique, decurrent on one side. 

 Nerves frequently dichotomous. This Fern has been found only 

 in fragments. It seems to have been a thick fleshy frond, but 

 the specimens are insufficient to show its habit of growth. Its 

 nearest allies seem to be C. Villiersi, Sternberg [Neuropteris ViUiersi, 

 Brongn.), and Cyclopteris JieterophyUa, Goeppert ; but it differs 

 from both. 



Cyclojjferis, s. n. (?) Many fragments occur in Mr Hartt's col- 

 lections of a very large Cyclopteris which may possibly have re- 

 sembled C. Brownii of Perry in Maine, but the specimens are not 

 sufficient for its full description. 



Cyclopteris BocJcshiana, Goeppert. Fragments referable to this 

 species (if it is really a distinct species from C. ohtusa)^ are found 

 rarely in the St John shales. I retain the generic name Cyclopteris 

 for all these ferns, so eminently characteristic of the Devonian as 

 distinguished from the Carboniferous ; not that I have any certainty 

 that they belong to one natural genus, but because they resemble 

 each other in venation, and the attemj^ts to arrange them in such 

 genera as Acliantites and Nceggerathia are evidently injudicious. 



Keuropteris jjolymorjjha, Dawson (Fig. 192, C). Pinnate or bipin- 

 nate. Rachis or secondary rachis irregularly striate. Pinnules vary- 

 ing from round to oblong, unequally cordate at base, varying from 

 obtuse to acute. Terminal leaflet ovate, acute, angulated or lobed. 

 Midrib delicate, evanescent. Nervures slightly arcuate, at acute 

 angles with the midrib. This fern is very abundant in the shales 

 near Carlton, at St John. At first sight it appears to constitute 

 several species, but careful comparison of numerous specimens shows 

 that all the various forms may occur on the same frond. In its 

 variety of forms it resembles N. heterophylla, Brongn., or N. hirsuta, 

 Lesquereux ; but it differs from the former in its delicate midrib and 

 acutely angled nervures, and from the latter in its smooth surfiice. 

 In the more recent collections of Mr Ilartt there are very fine and 

 perfect examples which I hope at some future time to figure. The 

 fragment here figured is a part of a terminal pinna. 



