84 DR ROBERT KIDSTON ON THE 



1885. Archnopteris Crepini, Stur, Carbon-Flora d. Schatz. Schichten: Die Fame, pi. xxv. figs, la, lb, 



2, and 3. 

 1885. Archxopteris Sauveuri, Stur, ibid., pi. xxxvi. fig. 2. 

 1893. Sphenopteris spiniformis, Kidston, Trans. York. Nat. Union, part xviii. p. 103. 



Horizon and Locality. — Roof of New Mine Coal: Clattershall Colliery, Brettell 

 Lane. 



Sphenopteris Schatzlariana Stur (emend.). 



1885. Diplothmema Schatzlarense, Stur, Die Fame : Carbon-Flora d. Schatz. Schichten, p. 325, pi. xxix. 



figs. 10, 11, pi. lxiv. fig. 2. 

 1913. ,, ,, Gothan, Oberschlesische Steinhohlenftora, i. Theil, p. 75, pi. viii. fig. 5. 



Remarks. — The genus Diplothmema Stur, in which he includes the above species, 

 was founded for certain ferns or fern-like plants in which more probably the petiole 

 than the rachis of the primary pinnae bifurcated ; the part below the fork was naked, 

 while the leafy portion was borne on the resulting forks or arms. 



A.s employed, this genus seems to bring together forms characterised in many cases 

 by little or nothing in common except a bifurcation of the petiole, and becomes in fact, 

 as generally used, practically another name for Sphenopteris Brongniart, if we add 

 to that genus the additional character of the bifurcation of the petiole in certain of 

 the species, and the use of the genus infers no additional knowledge of the affinities or 

 nature of the plants it embraces. 



I am aware that most paheobotanists have adopted the genus Diplothmema in a 

 more or less restricted sense than that originally proposed by Stur, but I have not 

 seen my way to follow this course, as it does not appear to be any real advance on the 

 old form genus Sphenopteris ; and even as a form genus, above which rank Diplothmema 

 does not rise, specimens showing the Diplothmema character are so rarely found 

 that as a means of provisionally separating certain forms it is of little practical value. 



But the course I adopt raises a difficulty in the case of Diplothmema Schatzlarense 

 Stur, for it cannot be simply removed from Diplothmema and placed in Sphenopteris, 

 as there is a Sphenopteris Schatzlarensis Stur, sp., already, the Hapalopteris 

 Schatzlarensis Stur (pars). As a means, therefore, of getting over this difficulty I have 

 altered the specific name from Schatzlarensis to Schatzlariana. 



Sphenopteris Schatzlariana is rare in Britain, but I have already seen it from the 

 Yorkshire and North Staffordshire Coal Fields. 



Horizon and Locality. — Roof of Fireclay Coal : Doulton's Clay Pit, Netherton, 

 near Dudley. 



Cf. Sphenopteris Sancti-Felicis Stur, sp. 

 PI. X. figs. 8 and 8a. 



1885. Diplothmema Sancti-Felicis, Stur, Die Fame: Carbon-Flora d. Schatz. Schichten, p. 301, 

 pi. xxix. fig. 1. 



