40 



BRITISH EOCENE FLORA. 



Helvet.' shows that the separation cannot be maintained ; for in the drawings there are 

 in places seven veins in L. helvetica to five in L. stiriaca ; while comparisons of the 

 tracings of Heer's figures,^ here reproduced, show that L. stiriaca is really the more 

 strongly toothed. It is impossible, in fact, to compare the figure of L. stiriaca, vol. i, 

 pi. viii, with that of L. helvetica, vol. iii. pi. cxliii, fig. 2, without recognising that 

 the latter is the upper part of the frond of the former. The species was founded upon 



YiG. \(,.—L. helvetica. ' Flor. Tert. V\g. \1 .—L. stiriaca. Ibid., vol. i, YiG. I'&.— G. stiriaca (1). ' Fl. foss. Arct.,' 

 Helv.,' vol. lii, pi. cxliii, fig. 2 (part J. pi. viii, fig. 4. pi. xlv, fig. 7. 



insufficient material, and should have been annulled when the more perfect specimens 

 were figured. Specimens of L. dalmatica which we have received present in like 

 manner no distinguishing specific characters, and should not remain separated. 



In the ' Flora Fossilis Arctica,' p. 87, pi. xlv, fig. 7, we find a portion of a pinna 

 figured under this name from Atanekerdluk, in Greenland. It possesses, however, 

 according to Heer's description, only three ternary veins on each side of the pinnule ; 

 while in the description of the Swiss form six to seven were essential to the species, and 



Fig. 19.— G. stiriaca. ' Flora of Fig. 20.— G. stiriaca. Ibid., fig. 13. Fid. 21.— G. stiriaca. Enlarged by 



Bovey,' pi. v, fig. 14 (part). Mr. Fitch. 



specimens possessing fewer are separated. He therefore seems to modify his specific 

 characters to include it, and in modifying them thus, leaves them sufficiently open to 

 1 Figure 16 shows the strongest denticulation present in the drawing of the fine specimen of L. helve- 

 tica in the third volume. 



