362 MR ROBERT KIDSTON ON THE FOSSIL FLORA OF THE 



to the rachis by their whole base, lower attached by a short footstalk, arti- 

 culated. Anterior basal angle of pinnule rounded, posterior basal angle slightly 

 auricled. Medial vein flexuous, and extending almost to the apex. Lateral 

 veins dividing several times, anastomosing, and forming an irregular 

 network. Meshes next the midrib longer than those further removed from 

 it. Terminal pinnule lanceolate. The frond also bears large cyclopteroid 

 pinnules. 



Remarks. — I am indebted to Mr George West, Camerton, for the fine speci- 

 men of this species shown on PI. XXI. fig. 6. From the inequality of the pinnae 

 on opposite sides of the rachis, the example is evidently only a pinna. At the 

 apex are several large simple lanceolate pinnules; on the third highest pinna 

 of those preserved, on each side of the terminal pinnule are a pair of almost 

 semicircular pinnules (fig. Qa x 3) attached to the rachis by their whole base. 

 On the lower pinnse the pinnules are oblong, with occasionally slightly tapered 

 apices. 



The veins form a very loose and irregular network. Those next the 

 flexuous midrib are elongated in the longer direction of the pinnule, i.e., more 

 or less parallel with the midrib. The meshes formed by the subsequent dicho- 

 tomies of the veins are directed more upwards and outwards, and become 

 smaller towards the margin of the pinnule. The reticulation is formed rather 

 by a bending of the veins towards each other than by their actual union. 

 The pinnules on the main figure are not so large as some shown at the 

 part indicated by an x. Zeiller figures a cyclopteroid pinnule of this 

 species (loc. cit., fig. 4). These were probably borne on the main rachis as in 

 Neuropteris. 



A comparison of my example with Romer's Dictyopteris Hoffmanni leaves 

 no doubt as to the identity of the two plants. But it seems equally clear that 

 D. Hoffmanni, Romer, is only a more perfect specimen of D. Miinsteri, Eich., sp., 

 and this opinion has already been indicated by Zeiller.* 



Through the kindness of Dr Weiss I have been enabled to compare a speci- 

 men of J). Hoffmanni from Piesberg (the original locality of this species) with 

 the Camerton plant; their nervation is similar, but in the size of the pinnules 

 the Piesberg example agrees more with the figures of D. Miinsteri, as given by 

 Zeiller, than the plant figured by me. 



The presence of the large terminal pinnule does not seem to be a constant 

 character, for on some of the specimens of D. Miinsteri, figured by Zeiller, 

 which agree exactly on their nervation with the specimen of I). Hoffmanni sent 

 me by Dr Weiss, the terminal pinnules are comparatively small. 



Locality : — Camerton. 



* Bull. soc. rjeol. de France, 3 C ser., vol. xii. p. 197. 



