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XVII. Contributions towards the History of Zamia Gigas, Lindl. §- Jltitt* By AY. C 



Williamson, F.B.S., Professor of Natural History in Owens College. Com muni 



cated by William Caehuthers, Esq., F.L.S. 



Bead June 4th, 1868. 



(Plates LII. & LIII.) 



THE rich geological district known as the "Yorkshire Coast" has furnished no more 

 interesting subject for investigation than the Zamia Gigas, Lindl. & Hutt. The frond ol 

 this plant was first figured in Young and Bird's ' Geological Survey of the Yorkshire 

 Coast 5 (tab. 2. fig. 6). In Prof. Phillips's 'Geology of the Yorkshire Coast' a few leaf- 

 lets were given under the name of Cycadites gramineus (tab. 10. fig. 2). It was after- 

 wards figured, from one of my drawings, in Lindley and Ilutton's 'Fossil Flora' 

 (tab. 165), under the name of Zamia Gigas, and I learn from M. Adolphc Brongniart 

 that this represents Zamia Mantelli of his < Prodrome' (p. 199). 



In Young and Bird's work some curious fossils are represented whote nature was 

 wholly unknown to the authors; but they suggested that they might be related to the 

 frond already referred to. This suggestion was based upon the fact that the two fossils 



in the same stratum, and not upon a study of their structure ; nevertheless 



it is probablv correct. 



In 1832 my father drew my attention to some fine specimens of these anomalous 

 objects, which he had just discovered at Hawsker. In 1833 I accompanied him to this 

 locality and succeeded in ohtaining additional illustrative specimens, so that, in a memoir 

 presented to the Geological Society of London in May 1834, I ventured to sugg -that 



found 



these organisms were « apparently connected with the fructification of a C£» (Geo! 

 Trans. 2nd series, vol. v. p 230). Nothing further was published ««•*>£ *«T*°J* 

 an imperfect example figured in Mantell' s • Medals of Creation/ un il ^ 

 brief notices appeared in the • Proceedings of the Philosophical Socie > r«f 1 ^ hsh. e 

 one bv James Yates Esq P R.S., who has laboured ddigently in accumulating spec. 

 Zf£Z£5 £ Cycads', and the other by myself. In the ^co- 

 cation severa! points were specified which ^her^ny^ ^ ; = ^ 

 were advanced hypothetical^, which I have since found to be eitlier * y 



to require considerable modification. collections of the Yorkshire 



More recently I have examined additional s P ecim ;^; U * h '^f Scarborough, and Mr. 

 1'hilosophical Society, of the late Dr. Mur ? and M^ ***££ > 

 %ley of Whitby. Through the latter f^T} 1 ^ of which Soc iety not only 

 Wonging to the Philosophical Society of Whitby, » °* me J, excrcise 



allowed me the use of them, hut, with ^M^^ ^ ^ 



* I have employed, throughout, the name given by Lmcuey ^ ^^ ^ ^.^ ^ ^ done me the honour 



of associating my name. 

 VOL. XXVI. 



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