APPENDIX. ; 103 



To accept Dr. Ramsay's belief, it would be necessary to over-, 

 look altogether the middle (or 3rd) and much of the 2nd forma* 

 tions of the Permian system, 



Reverting to Dr. Ramsay's grounds for assigning a brackish- 

 lacustrine origin to the Permian rocks in general, I propose, in 

 the next place, to notice the one founded on the " poverty in 

 number of the fossils " they contain. 



Conclusions on this point are not to be influenced by consi. 

 derations arising from the study of individual characteristics, 

 but of general facts. Evidently Dr. Ramsay has been in- 

 fluenced in his belief by the fact that brackish lakes, com- 

 pared with sea-basins, are sparsely inhabited by molluscs \ 

 but he overlooks another fact of importance, that depths 

 exceeding 100 fathoms are not so prolific in animals of the kind 

 as shallower bottoms. " Poverty in number " as a feature of 

 deep-sea life affords a more satisfactory explanation of the 

 point in question than the corresponding feature in its brackish^ 

 water relations. 



The same argument attaches to the t( dwarfed aspect " of the 

 Permian, invertebrates ; for the term " dwarfed " is equally 

 applicable to a deep-sea fauna, which usually consists of small 

 and delicate species. Such forms as Productus horridus, with 

 its long projecting hinge-spines, and Fenestella retiformis, with 

 fragile fronds six to eight inches in spread, and several other 

 tender organisms could only live at considerable depths, where 

 still water prevailed. But it cannot be said that the Permian 

 fossils are particularly dwarfed; the Bryozoon just referred to 

 is a strong fact against any statement of the kind. Spirifer 

 alatus does not compare unfavourably with most of its Carboni- 

 ferous congeneric species; and Camarophoria multiplicata is a 

 match for the largest of its allies, C. Kingii (Davidson), of the 

 Carboniferous limestones. Several other Permian fossils could 

 be mentioned in this comparison. It is quite true that, so far, 

 the Permian rocks have not yielded any thing equal to Productus 

 giganteus and P. ponderosus and other heavy fossils, especially 

 corals ; but these may be safely consigned to shallow seas. 



It is necessary to mention that the Permian palliobranchs 

 were denizens of deep water ; for in fossiliferous beds which 

 bear all the marks of having been formed in shallow water 

 these shells are absent. Certain beds of coralloidal limestone 



