328 MR ROBERT KIDSTON ON THE FOSSIL PLANTS OF THE 



X'uropteris crenulata, Renault, Cours d. botan. foss., vol. iii. p. 174, pi. xxix. fig. 14. 

 Neuropteris crenulata, Zeiller, Flore foss. terr. houil. d. Comentry, part i. p. 233, pi. xxvi. fig. 1 ; pi. 

 xxvii. figs. 1-5. 



Description. — Frond very large, and much divided ; pinnules cyclopteroid, oval, 

 subcordate to narrow-oblong (according to the position they hold on the frond), with 

 blunt apices, subopposite or alternate. The uppermost pinnules more or less united by 

 their base to the rachis. Medial nerve of pinnule slightly flexuous, and giving off 

 upward-directed dichotomous veinlets, of which there are at the margin of the pinnule 

 about twenty ultimate divisions in 1 centimetre. Margin of pinnule dentate-serrate, 

 the ultimate divisions of the veins extending into the teeth. 



Remarks. — This species apparently attained to great size, as shown by the excellent 

 figures given by Zeiller (loc. cit.), but whether the fern was tripinnate or decompound in 

 its ramifications, cannot at present be determined. It was at all events much divided. The 

 pinnules vary greatly in form according to their position on the rachis. The cyclopteroid 

 pinnules were evidently borne on the main rachis or on the raches of the chief divisions 

 of the frond. The fronds of many species of Neuropteris attained, I believe, to very- 

 large dimensions. 



The pinnules at the base of the pinnae of Neuropteris crenulata are ovate or sub- 

 cordate, from the base of the pinnae upwards the pinnules gradually increase in length, 

 and diminish slightly in width till they are narrow-oblong towards the apex of the pinnae ; 

 they again decrease in size, and the pinna ends in an oblong terminal pinnule. It is 

 almost impossible to describe in language the various forms of the pinnules of this species 

 their shape depending on their position on the frond ; but they can be easily learnt by 

 studying the figures given by Zeiller in his Flora of the Comentry Coal Field. The 

 nervation is somewhat lax, though fine. In the small specimen figured on Plate I. fig. 2, 

 which shows the upper portion of a pinna, the pinnules are united by their bases to the 

 rachis, a character usually observed on the apical portions of the pinnae of Neuropteris. 

 The central vein is slightly flexuous, and the secondary veins which spring from it run 

 upwards and slightly outwards, and thus have a long course before reaching the margin 

 of the pinnule. In the specimen figured there are about twenty ultimate divisions of the 

 veins at the margin of the pinnule in 1 centimetre. According to Zeiller there are from 

 seven to ten in the same space. This difference may arise from the different position on 

 the frond of the pinnules in which the veins were measured, or the ultimate and finer 

 divisions may not have been preserved in the specimens measured by Zeiller, though 

 this does not appear to be probable from the figures of enlargements given by him. The 

 whole of the margins of the pinnules of the Kilmaurs specimen are dentate-serrate, and 

 this character at once distinguishes the species from all other Neuropteris, as far as I 

 know them. In Zeiller's specimens, some of them had pinnules with entire margins, 

 and in others the crenatures appear to be only on the upper part of the pinnules. The 

 Kilmaurs specimen appears to be identical with the small specimen figured by 

 Brongniart. 



