I860.] KIRKBY — PERMIAN FOSSILS. 419 



genus Psaronltes as being particularly distinctive of the Pothliegende. 

 From the slight acquaintance I possess with this flora, I am not aware 

 that it differs gencrically from the preceding flora of the Coal-mea- 

 sures; and with respect to Psaronites, it is undoubtedly a Carboniferous 

 genus, having occurred in the coal-fields of France and the United 

 States*. It is for those who have studied palaeozoic rocks .and or- 

 ganic remains to decide whether so subordinate a development of 

 generic types can be compatible with the systematic distinction of 

 the Permian strata. 



It is undoubtedly difficult to define the precise amount of value 

 attached to the term " system" ; and perhaps it is not to be expected 

 that perfect uniformity of value can be adhered to in systematic 

 groups of strata ; still it is highly desirable to approximate to this 

 for sound classification. At any rate it seems practicable to observe 

 a greater degree of consistency in the division of the palaeozoic strata 

 into primary groups than exists in the quaternary system now 

 adopted. For, if we are to consider the whole of the Silurian rocks 

 and the various phenomena they express as only sufficient to consti- 

 tute one system, upon what principles of classification are we to 

 grant the same value to the Permian rocks, the importance of which 

 in every respect is less than that of cither the Upper or Lower Silu- 

 rian groups ? If the one merely suffice to establish a system, surely 

 the other must fall greatly short. Or if the latter suffice, does not 

 the former more than suffice ? 



It may be contended that magnitude is not the only clement in 

 constituting systems, nor yet, perhaps, the character of organic re- 

 mains, but that conformability, or the converse, is of more import- 

 ance than either, or both. Now it scarcely comes within the scope 

 of this paper to discuss the merits of the Permian system in this light. 

 My remarks are based on the palreontological aspects of the quesf ion, 

 which I hold to be of infinitely greater consequence in the grouping 

 of strata than the relative position which strata occupj\ Conform- 

 ability of strata docs not prove that they were deposited with regu- 

 larity, or that they do not belong to widely separated periods <>r 

 time; nor does unconformability demonstrate the dose of one period 

 and the commencement of another; for it has yet to be proved that 

 a general disturbance of strata ever took place — that unconformability 

 is ever more than local. I therefore maintain t li.it it is chiefly upon 

 life-phenomena that we must rely in the classification of rocks, and 

 that, in all attempts to arrive at an approximation to the relative 

 value of ancient periods of time, the evidence afforded by organic re- 

 mains must be of greater importance than that of the rocks contain- 

 ing the remains. 



In thus attempting to show the close relationship that exists 

 between the Permian anil Carboniferous life-groups, I speak only 

 according to the present state of palaeontology. Tin- later advances 

 of this science seem t> tend towards the abrogation of all natural 



SVStemS; ami it i- not unlikely that ultimately geologists ami palae- 

 ontologists will h&Ve to admit, BS 80016 perhaps admit now, that all 

 * Lycll's Elements of Geology, 1th edit, p, 307i 



