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V. — On the Fossil Flora of the Yorkshire Coal Field. (Second Paper.*) 

 By Kobert Ktdston, F.R.S.E., F.G.S. (With Three Plates.) 



(Read 20th July 1896.) 



Among the specimens from the Yorkshire Coal Field which have been collected by 

 Mr W. Hemingway, Barnsley, and submitted to me for examination at various times, are 

 the remains of several cones which are referable to the genus Sigillariostrobus, Schimper. 



Notwithstanding the great frequency of the genus Sigillaria in the Coal Measures, 

 and especially in the Middle Coal Measures, examples of their fructification are very rare. 

 This is the more remarkable, as specimens of Sigillaria, showing cone scars, though not 

 common, are occasionally met with. Possibly, however, the apparent rarity of Sigil- 

 larian cones is due, in part, to our inability at present to distinguish them in all cases 

 from cones generally placed under the name of Lepidostrobus, which latter genus there is 

 every reason to believe comprises cones that belong to several genera of Lycopods. 



A Sigillaria occurs in the Upper Coal Measures of Somersetshire, which I have 

 recorded under the name of Sig. tessellata (but which differs slightly from the typical 

 form), that frequently shows verticils of cone-scars ; but I could never refer any of the 

 many forms of Lepidostrobi, occurring in the same beds, to that or any other Sigillaria. 



It is quite possible that the cones I described as Lepidostrobus (?) spinosus t and 

 Lepidostrobus squarrosus^ may belong to Sigillaria, but on this point we cannot 

 speak with any certainty. In the case of the two cones to be described in this paper, 

 no doubt can remain as to their Siffillarian nature. 



Although the genus Sigil (aria was founded by Brongniart in 1822,§ nothing was 

 known of the internal organisation of Sigillaria till 1839, when the same distinguished 

 author published his " Observations sur la structure interieure da Sigillaria elegans 

 comparee a celle de Lepidodendron et des Stigmaria et a celle des vegctaux vivants."\\ 



Previous to the publication of Brongniart's paper no data existed from which the 

 affinities of the genus could be suggested, and owing to imperfect knowledge of the 

 internal structure of fossil and at present living allied plants, some of the structure 

 displayed by the now classic specimen was misinterpreted, and from then till the 

 present time, notwithstanding the description of undoubted Lycopodiaceous Sigillarian 

 cones by Zeiller,! some botanists are still very reluctant to give up their old ideas of 

 the Cycadaceous affinities of Sigillaria, as originally suggested by Brongniart, and still 

 seem to hesitate to place Sigillaria amongst the Lycopodiacese. 



* " On the Fossil Flora of the Yorkshire Coal Field " (first paper), Trans. Roy. Soc. Edin., vol. xxxviii. part ii. No. 5, 

 pp. 203-223, with three plates, 1896. 



t Trans. Roy. Soc. Edin., vol. xxxvii. p. 342, pi. iv. figs. 13-14, 1893. 



t Trans. Roy. Soc. Edin., vol. xxxvii. p. 341, pi. ii. fig. 7 ; pi. iii. figs. 11-12, 1893. 



S " Sur la classification des vegetaux foss.," p. 9, Mem. Mustfum d'hist. nat., vol. viii. Paris. 



|| Archives du Museum, vol i. pp. 405-461, pis. xxv.-xxxv. (i.-xi.). 



IT Zeiller, Ann. d. Sc. Nat, 6*. ser., " Bot," vol. xix. p. 256, plates xi., xii., 1884 ; also in Flvre foss. du Bassin 

 Jiouil. d. Valenciennes, p. 591, 1888. 



VOL. XXXIX. PART I. (NO. 5). H 



