460 Geological Society. 



that when the wish of the Council to assist in describing and pub- 

 lishing them is generally known, we shall probably never want such 

 a supply, as will enable us to connect with every future part of our 

 Transactions some contribution to fossil Botany. Great benefit will 

 thus be produced, by circulating information at present locked up 

 and unavailing ; and the specimens lent to the Society for illustra- 

 tion, will be rendered doubly valuable to the proprietors themselves. 



The Botanical paper, in the last part of our Transactions, is that 

 of Dr. Buckland, on the Ct/cadeoid'ece ; a new family of fossil plants, 

 discovered in the isle of Portland, and obtained most probably 

 from a stratum immediately above the oolitic beds, which contains 

 also lignite, with the silicified trunks of dicotyledonous trees. 



On the suggestion of Mr. Brown, these fossils have been con- 

 sidered as belonging to a famil}' very nearly related to, but perhaps 

 sufficiently distinct from, the recent Cycadcce : and the observations 

 of this distinguished Botanist, with respect to the stem or caudex of 

 this family, are illustrated by sections represented in the plates 

 which accompany Dr. Buckland's paper. 



The family of Cycadeae consists at present of two genera, Zamia 

 and Cycas. In certain Zamite, Mr. Brown states, there is one 

 narrow vascular circle, divisible into radiating plates, and situated 

 in the midst of the cellular substance of which the stem is in a great 

 part composed. In Cycas revoluta, a second circle is added ex- 

 ternally, at a small distance from the first; and in Cycas circinalis, 

 (according to the only section of this plant yet published,) the circles 

 are more numerous, — the outermost being still considerably re- 

 moved from the circumference. 



The fossil stems, which are the immediate subject of Dr. Buck- 

 land's paper, like the recent Cycadete, are not covered with true 

 bark, but have a thick case, made up of the basis of decayed leaves, 

 which externally form rhomboidal compartments, similar to those of 

 the recent plants. The internal structure in the fossils, so far as 

 hitherto examined, resembles that of the Cycadeae, except in the 

 more external position and greater breadth of the circle or circles 

 visible in the section of the stem ; a character whereby, Mr. Brown 

 is of opinion, this fossil family approaches more nearly, than the 

 Cycadete, to the ordinary structure of dicotyledonous woods ; and 

 consequently may be considered as supplying, from the fossil world, 

 a link, which helps, in some degree, to connect the still distant 

 structure of the Cycadea; with that of the nearest existing family, 

 the Coniferae. 



M. Adolphe Brongniart's publications on the History of Fossil 

 Vegetables*, though produced in another country, are too im- 

 portant to our inquiries not to be mentioned here. Some fear, 

 perhaps, may be entertained, that his data are not yet sufficiently 



* " Prodrome d'une Histoire des Veg^tHUX Fossiles ;" published also as 

 the article " Vcgctaux Fossiles," in theDictionnaire des Sciences Naturelles ; 

 Paris, 1828. — " Considerations Generales siir la Nature de la Vegetation," 

 &c. Ann. des Sciences Naturelles; December, 1828.— " Histoire des V^ge- 

 taux Fobsiles," &c., publishing in Numbers. 



extensive 



