1883.] Anomalous Oolitic and Palceozoic forms of Vegetation. 223 



immediate result lias been the limitation of tlie genus Williamsonia 

 to these reproductive organisms, and the restoration of the name 

 Zamia gigas to the stems and fronds to which it was originally 

 applied, and respecting the Cycadean character of which there is no 

 doubt. 



What, then, are Williamsonia gigas and its allies ? Dr. Nathorst of 

 Stockholm has published a memoir,* in which he suggests that it has 

 belonged to the curious fungoid-looking order of the Balanophorae. 

 This suggestion I am unable to adopt. An inspection of the shapeless 

 and shrivelled Balanophorae, seen in any herbarium, will suffice to 

 show the improbability of their having ever been fossilized into the 

 elegant and sharply defined forms of the Williamsonia gigas. The 

 Marquis of Saporta is inclined to believe that it has been the in- 

 florescence of a sj^adicifloral Monocotyledon. This supposition seems 

 to me quite as devoid of probability as that of M. Nathorst. The 

 texture of its foliar organs still appears to me suggestive of an 

 abundant supply of the sclerenchyma, which produces the firmness, 

 ahnost rigidity, so characteristic of the foliage of the Cycads ; and I 

 am far from certain that even yet its nearest relatives will not be 

 found in that group. Anyhow, for the present we can only conclude 

 that, whilst Williamsonia represents an undetermined form of vegeta- 

 tion, the importance of the genus is alike evident from its morpho- 

 logical i^eculiarities and its wide geographical diffusion. 



I have long possessed this specimen of a curious stem from the 

 beds in which Williamsonia gigas occurs, and which has been briefly 

 described by Sir Charles Bun bury under the name of Calamites 

 Beanii.^ The occurrence of a true Calamite in the Oolitic rocks 

 would be a palseontological fact of considerable imjDortance ; but I 

 cannot admit the Calamitean character of the plant so designated. 

 Indeed Sir Charles Bunbury kindly informs me that he has no strong 

 convictions about its Calamitean nature. So far as external appear- 

 ances are concerned, it more closely resembles the stem of one of the 

 arborescent Graminese. But such appearances have very little Tax- 

 onomic value. Nevertheless, the plant stands out in prominent 

 distinctiveness from amongst the Ferns, Cycads, and Conifers that grew 

 around it, forcibly suggesting the idea of an arborescent Monocoty- 

 ledon ; and if such has been its character, its position amongst these 

 older Oolites would make it, if not the earliest, one of the earliest 

 representatives of the Monocotyledonous group. In that case it repre- 

 sents a link in the ontological chain of vegetable life of great im- 

 portance, though one of w^hich at present we can make no use. 



Though we have no great difficulty in determining what are and 

 what are not ferns, the difficulty is often insuperable when we try to 

 ascertain with which of the varied fern-types any fossil form presents 



* Ofversigt af KoDgl-vetenskaps-Akademiens Forhandlingar, 1880, : 

 Stockholiu. 



t ' Quarterly Journal of the Geological Society of London,' vol. vii. (1851^ 

 p. 189. ^ ^ 



Vol. X. (No. 76.) q 



1^ 



