90 FOSSIL PLANTS. 



Neuropteris heterophylla, Ettingshausen (Die Foss. Flora d. Mahr.-Schles. 

 Dachschiefers. p. 96, fig. 4, and pi. vi. fig. 4), aDd N. Loshii Ettingshausen 

 (loc cit. p. 95, pi. vi. fig. 2) ; N. Loshii and N. heterophylla, Feistmaiitel 

 (Kohlenkaikvo'r. bei Rothwaltersdorf., Zeitsch. d. Deut. Geol. GeseU. 

 vol xxv p 520 pi. xvi. fig. 20), are not referable to N. heterophylla, Brongt., 

 but are the N. antecedens, Stur (Culm Flora, heft 1, p. 53, pi. xv. figs. 1-6). 



Cydopteris trichomanoides, Brongt., has been found attached to Neuropteris 

 Loshii (N. heterophylla), and figured by Eoehl (Vers. d. Steink. Form. 

 Westph. pi. xvii.), and I have seen a specimen affording similar evidence as 

 to the union of Cydopteris trichomanoides with Neuropteris heterophylla. 



In the Coalbrook Dale and Dudley Coal Fields, where Cydopteris tricho- 

 manoides is very common, the pinnules vary exceedingly in form and size, 

 and do not appear to be separable into the various species which have been 

 created for their reception. 



On specimens of Neuropteris Scheuchzeri, Hoff., from the Radstock Coal 

 Field, I have seen gradations in form, from the typical acute pinnules to 

 others truly cyclopteroid on the same pinna, and I have also observed 

 similar differences in the shape of the pinnules situated on the main axis of 

 this species ; hence outline is of no specific value in dealing with isolated 

 pinnules of this kind. 



I believe that Cydopteris dilatata, Cydopteris oblata, and Cydopteris obliqua 

 are all referable to Neuropteris heterophylla. 



Grand 'Eury mentions that he finds Cydopteris oblata, L. and H., to be only 

 the pinnule of a Neuropteris, but he does not state to which species it was 

 united.* 



In indifferently preserved cyclopteroid pinnules the finer veins are not 

 shown, and the stronger veins only being preserved give the pinnule a 

 different aspect ; but many specimens which at first sight appear to differ 

 in this manner from Cydopteris trichomanoides have on more careful exami- 

 nation been shown to' belong to this species, as at certain better preserved 

 parts of the specimen, especially near the margin, the smaller veins were 

 shown. 



To this class belongs, I believe, Cydopteris orbicularis, Brongt., the chief 

 character between which and Cydopteris trichomanoides (irrespective of form, 

 which we know varies in these pinnules, depending on their position on the 

 fern), being its much less numerous and more distant veins. 



The type of Brongniart's Cydopteris orbicularis (Hist. d. Veget. Foss. 

 pi. xli. fig. 2) is in the Oxford Museum, and Professor Moseley has kindly 

 furnished me with the following particulars regarding itf : 



" The outline of the margin of the pinnule shown in the figure is purely 

 imaginary, the margin not being included at all within the pebble, or if 

 preserved anywhere, only exactly coinciding with the pebble's surface. The 

 veins towards the margin are much more numerous than represented to be in 

 the figure." He further states that in a given space on the margin of the 

 figure only 13 or 14 veins are represented, whereas in a corresponding interval 

 on the fossil he counted 49. Hence Cydopteris orbicularis, Brongt. (loc. cit. 

 pi. Ixi. fig. 2), is evidently the same as his Cydopteris trichomanoides. As to 

 the other figure of Cydopteris orbicularis, given by Brongniart, of course I 

 cannot speak, but think it is most probably a condition of Cydopteris tricho- 

 manoides, where the finer veins have disappeared. 



Again, many of these pinnules occurring in ironstone nodules do not appear 

 to be preserved in their entirety : hence we find in different examples a 

 varying number of veins in a given marginal space, the number very much 

 depending on whether we have the real margin of the pinnule before us, or an 

 apparent one. As the veins repeatedly bifurcate, they become more numerous 

 as they recede from the base of the pinnule : thus many examples which appear 



* Flore Carbon, du Dgp. de la Loire, p. 379. 

 t In letter, dated 17th August, 1883. 



