404 MR ROBERT K1DSTON ON THE FOSSIL PLANTS IN THE 



trifoliolata, Artis, sp., with which it had been previously identified. In this latter 

 species the pinnules are much larger and characteristically trilobate, and the plant has a 

 different mode of growth, — the importance of these characters, though difficult to describe 

 adequately in words, are very obvious when actual specimens of the two plants are 

 compared. The type figure of Sph. trifoliolata * is a very characteristic drawing of the 

 plant, and shows the differences more clearly than can be pointed out in a written 

 description. 



In PI. II. fig. 1, the pinnae have an almost linear outline, while in Sphenopteris 

 trifoliolata they are more deltoid. Some of the pinnules of Sphenopteris Marratii, 

 especially on the upper pinnae, are trilobate (fig. lb), but on the lower pinnae, where the 

 trilobate pinnules are characteristic in Sph. trifoliolata, they do not occur on Sph. 

 Marratii, or only very rarely. 



Fig. 2 is from another small specimen of the same species, and shows portions of 

 two pinnae, evidently belonging to a lower part of the frond than that from which fig. 1 

 has been derived. It is laxer in its growth, the ultimate pinnae and pinnules are more 

 distant, but still possess the same characters as those of fig. 1. 



The pinnules at the base of the pinnae are often notched or obcordate, those higher on 

 the pinnae obovate. The terminal pinnules are blunt, and frequently lobed. The number 

 of pinnules on the ultimate pinnae varies according to the position of the pinnae on the 

 frond. 



Fig. 1 is probably the terminal portion of a frond, though it may be only the 

 termination of a primary lateral pinna. 



Sphenopteris Marratii may possibly be the same plant as that figured by Stur as 

 Sphenopteris trifoliolata,^ but in the absence of enlarged drawings of the pinnules of his 

 fern, one cannot be certain of their identity. One point, however, is certain, that the 

 fern named Diplothmema trifoliolatum, Artis, sp., by Stur, is not that plant. 



Of the references Stur gives for Sphenopteris trifoliolata, Artis, sp., only that to 

 Artis' figure is correct. The Sphenopteris numularia figured by Andr^,| and the 

 Sphenopteris trifoliolata given by Brongniart,§ not being referable to Artis' species. 

 In fact, Sphen. trifoliolata, Artis, sp., seems to be very much misunderstood on the 

 Continent. 



Since preparing the catalogue of Palaeozoic Plants in the British Museum, I have had 

 considerable opportunities of examining specimens of Sphen, trifoliolata, and now think 

 that none of the figures issued under this name by Andr^e,|| Roehl,1T or Brongniart ** 

 belong to that plant. 



* Antedil. Phyt., pi. xi. 



t Carbon Flora, p. 346, pi. xix. figs. 1-4 (Diplothmema trifoliolatum). 

 Vorwelt Pflanzen, pi. xi. 



§ Hist. d. ve'gd. foss., pi. liii. fig. 3. 



|| Vorwelt Pflanzen, pi. ix. figs. 2-4. 



IT Foss. Flora d. Steink. Form. Westph., pi. xvi. figs. 3 and 16. 

 ** Hist. d. ve'ge't. foss., pi. liii. fig. 3. 



