8 BURDWAN7 Chap. I. 



majority are referred by Dr. McLelland* to the inferior 

 oolite epoch of England, from the prevalence of species 

 of Zamia, Glossopteris, and Tceniopteris. Some of these 

 genera, together with Vertebraria (a very remarkable Indian 

 fossil), are also recognised in the coal-fields of Sind and 

 of Australia. I cannot, however, think that botanical 

 evidence of such a nature is sufficient to warrant a satis- 

 factory reference of these Indian coal-fields to the same 

 epoch as those of England or of Australia; in the first 

 place the outlines of the fronds of ferns and their nervation 

 are frail characters if employed alone for the determination 

 of existing genera, and much more so of fossil fragments : 

 in the second place recent ferns are so widely distributed, 

 that an inspection of the majority affords little clue to the 

 region or locality they come from : and in the third place, 

 considering the wide difference in latitude and longitude 

 of Yorkshire, India, and Australia, the natural conclusion 

 is that they could not have supported a similar vegetation 

 at the same epoch. In fact, finding similar fossil plants at 

 places widely different in latitude, and hence in climate, is, 

 in the present state of our knoAvledge, rather an argument 

 against than for their having existed cotemporaneously. 

 The Cycadcce especially, whose fossil remains afford so much 

 ground for geological speculations, are far from yielding 

 such precise data as is supposed. Species of the order are 

 found in Mexico, South Africa, Australia, and India, some 

 inhabiting the hottest and dampest, and others the driest 

 climates on the surface of the globe ; and it appears to me 

 rash to argue much from the presence of the order in the 

 coal of Yorkshire and India, when we reflect that the 

 geologist of some future epoch may find as good reasons 

 for referring the present Cape, Australian, or Mexican 



* Reports of the Geological Survey of India. Calcutta, 1850. 



