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GEOLOGICAL MEMOIRS. 



Var. b. Much smaller. 

 Petit-Cceur. 



Several leaves of the same size are associated on the same stone 

 with Odontopteris obtusa and Cyatheites Schlotheimii. The leaf is 

 of the size of C. Bokschii, Gop., and therefore much smaller than 

 that of C. reniformis : its length and breadth are each about 10"'. 

 It agrees with it, however, in shape and venation, so that I have for 

 the present considered it as a variety. Possibly better specimens 

 may prove it to be a distinct species ; or else that the smaller leaves 

 belonged to the outer and the larger to the lower part of the entire 

 plant. The leaf is broad at the base, and moderately rounded and 

 reniform : its rim, as far as it is preserved, is entire : the veins are 

 fan-shaped, thick at the base, moderately curved and forked, be- 

 coming remarkably slenderer after the bifurcation. It differs from 

 C. Bokschii in the rounding at the base, and in the veins being less 

 close and being thickened at the base. 



14. Cyatheites Schlotheimii, St. sp. {Pecopteris cyathea, Brgn.) 

 Col de Balme ; Petit-Cceur. 



From the first locality we possess a very beautiful frond. The 

 leaf-stalk is moderately stout ; the pinnae very long and elegant ; they 

 have a great number of pinnules which only touch at the edge, and 

 do not overlie each other. This species is not unfrequent in the An- 

 thracite, and is one of the most widely distributed of the Ferns of 

 the Coal-measures in Germany, France, and North America. 



(Aus.) 15. Cyatheites arborescens, Brongn. sp. 



Col de Balme ; Petit-Cceur ; La Mure ; Montagne de Bacule 

 Carienne (Dauphine). 



This species is even more abundant than the preceding, and has 

 also been found in Styria. We possess several elegant fronds, which 

 exactly agree with Coal-measure plants. Bunbury considers this 

 species and the preceding to be the same, but I think erroneously, 

 since in this species the pinnae are slenderer, the leaflets smaller, 

 shorter and blunter, and hence the edges of the pinnae run in straighter 

 parallel lines. 



Var. b. C. platyrrhachis, Brongn. sp. 

 Petit-Cceur ; Col de Balme. 



On the reversed side of the same specimen which contains the 

 beautiful stems of the C. Schlotheimii. The pinnae and leaflets have 

 exactly the form of C. arborescens, and accordingly Goppert and 

 Unger unite the two ; but Brongniart distinguishes the above, as its 

 leaf-stem is very broad ; it is much broader and therefore much 

 thicker from its origin than in C. Schlotheimii. 



(*)16. Cyatheites Candolleanus, Brongn. sp. 



Montagne de Bacule Carienne (Dauphine), on the same slabs with 

 C. arborescens. 



