FROM THE SECONDARY ROCKS OF BRITAIN. <,77 



described it, an Endogen. The only other supposed indication of Tertiary Cgcmhm \» 

 the fragment of a leaf (Zamites arcticus) described by Goppert, from the Miocene )>eds I 

 Kook, in Greenland 1 . This specimen is not only imperfect, but it is so anomalous lliat 

 t-ven those who believe it to be Cycadean can find no analogous form either recent or 

 fossil. It cannot be supposed that Cycadece were absent from the vegetal ion of th« Ter- 

 tiary period 2 ; their non-discovery hitherto must be taken as another instance of the im- 

 perfection of the record of extinct life with which students have to deal. 

 I do not propose in this memoir to refer to the species of Cycade<e founded <>n foliage 

 . The detached fruits with which I am acquainted I have described in a paper on 

 Gymnospermatous Emits of the Secondary rocks 3 . I shall confine myself to th< 



v 



forms of stems which have been found in Britain, including also, where materials 



exist, the fruits and foliage associated with them, and examining the evidence their 



& 



- 



remains afford as to the relations they bear to the recent members of the Order. 



Bibliography. — In 1822 Mantell published an account of some v< jetablc f «sils he had 

 obtained from the sandstones of Tilgate Eorest 4 , the affinities of which he was unable to 

 determine. They were fragments of stems which were "composed of a cylindrical imbri- 

 cated axis, marked with interrupted longitudinal striae, and a corti. .1 layer covered exter- 

 nally with rhomboidal markings." He supposed that they might be fern* or pdms, or, 

 more probably, Euphorbiace®. Some time afterwards he sought the opinion of the mem- 

 bers of the Geological Society of London on these anomalous remains, and Messrs. Stokes 

 and Webb were appointed by the Council to describe and publish them in their Ti ns- 

 actions. In their report 5 they recognized the external resemblance the fossils bore to th 

 stems of Zamia and Cycas, but they held that they differed "from the-' or anj 



( 



known family in enclosing an internal body marked on its surface, and that ven diflfef 

 ently so from the external covering." They, however, placed the fossils in Oathrana, <• 

 genus established by Brongniart 6 for a group of stems previously included in Stern- 

 berg's genus Lepidodendron. , 



Presl, in 1825, in his synopsis of fossil plants, published in Count Stern!,,,-, I peal 

 work', separated the Tilgate fossils from Clathmria and referred them to <*»**, . >„- 

 bhshing for them the genus Bmklmdia. In a later systematic account of foss. plant. ■ ... 

 the same work (1835) this genus is altogether omitted, and no not.ee ,s taken at tM 



fossil for which it was established. . , . 



Brongniart, in 1828', examined at some length the affintttes of these «£"££ 



and believing that they agreed in the an-angement of then- parts w„h b r unk A 

 thor^a, he referred them to UUacece. This opinion was very general!; adopt, ,1 , 



1 S*. Jahrb. f. Mineralogic, 18B6, p. 113. d Kov de Be i g . Tu l. xxxvi. p. 6 



' CWans, in his , Flore Fossile du Ter, Cret. du Hamaut _ £■££ ^ % ^ „ , 

 ■* that some isolated Cycads are found in Tertiary strata ^ ™ *^ of the South Downs, pp. #, 43. 



'Seemann's Journal of Botany, 1867, p. 1. du Mus. vol. viii. (IS- W •* 9 - • 



Trans. Geol. Soc. ser. 2, vol. i. (1824) p. 422. ; **^ ^ ^^ d(> v , t : taux Foss i 



Flora der Vorwelt : Tentamen, p. xxxiii. 



a t • „ _ _ 



F oasile 



** ... i7 rt/ ii;phpr lien, nam. v^ " r 



Lindley, Introduction to Fossil Flora (1 -32), p. xln : Lndhtfier, ^^ ^ _ ^ ^ ^ % fo % f , 



R Pec. Plant. Foss. (1850), p. 314 ; Ettingshausen, Abhandl. d. K. K. geo . , ^ g 



