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Show 266 IMPERFECTION OF THE [CHAP. IX. covered in any secondary formation, .se~med :(ully to . t' f the belief that this great and distinct order h~d JUS I Y dd 1 d d in the interval between the latest been su en Y pro "?-ce . £ . ation But now we secondary and earhest tertiary oim II' ·, M I' b rna read in the Supplement to Lye ~ anua ' pu - I' ;{ d . 1858 clear evidence of the existence of whales i: t~e ~per greensand, some time before the close of the secondary period. . h · d I may give another instance, which from aving passe. under my own eyes, has much struck me. In a memoir on Fossil Sessile Cirripedes, I have. stated t~at, from the b Of existing and extinct tertiary spemes ; from the nexutmra oerrd inary abundance of t h e I. nd I' VI. d ~a I s of . many spe-cies all over the worl~, from the Arctic regions to the equator, inhabiting vanous zones of depths from the upp~r tidal limits to 50 fathoms ; from the perfect manne: In which specimens are preserved in the oldest tertiary beds ; from the ease with which even a _fragment of a valve can be recognis.ed; .fr?m all t~ese circ~mstances, I inferred that had sessile cunpedes existed dunng the secondary periods, they would certainly haye been preserv~d and discovered ; and as not one species has b~en discovered in beds of this age, I concluded that this great group had been sud~enly d~veloped at the commencement of the tertiary series. This was a sore trouble to n1e, adding as I thought one more instance of the abrupt ap-earance of a great group of spec~es. But my wo~k had hardly been published, when a skilful palreon~olog1st, M. Bosquet sent 1ne a drawing of a perfect specu:?en of an unmistakeable sessile cirripede, which he had ~1mself extracted from the chalk of Belgium_. An?, as. I~ to make the case as striking as possible, this sessile cunp~de. was a Chthamalus a very common, large, and ubiquitous genus, of which not one specimen has as yet been. f?u~d even in any tertiary stratum. Hence yve now positive Y know that sessile cirripedes existed during the secondary period; and these cirrip_edes might. h!l've bee~ the pro-genitors of our many tertiary and existing spemes. The case most frequently insisted on by palreonto1 o gists of the apparently sudden appearance of a whole CHAP. IX.] GEOLOGICAL RECORD. 267 ~roup of species, is that of the teleostean fishes low down ~n ~he Chalk. p~riod. ~his group includes the' large maJOrity of exrstrng species. Lately Professor Pictet has carried their existence one sub-st;o-e further back· and some palreontologists believe thaf certain much 'older fishes, of which the affinities are as yet imperfectly known, are really t~leostean. Assuming, however, that the whole of them drd appear, as Agassiz believes, at the co1nmencement of the chalk formation the fact would certainly be highly remarkable; but I dannot see that it ~vould b~ an _insuperable difficulty on my theory, unless It could hkewise be shown that the species of this group appeared suddenly and simultaneously throughout the world at this same period. It is almost superfluous to remark that hardly any fossil-fish are known from south of the e9-uat?r; and by running through Pictet's Palreontology It wrll be s~en t~at very few species are known from several formations In Europe. Some few families of. fish now have a confined range; the teleostean fish mrght for~erly have had a similarly confined range, and af!er having been la:gely developed in some one sea, mrght have spread Widely. Nor have we any right to suppose that the seas of the world have always been so freely open _from north to south as they are at present. Even ~t this day, if the. Malay Archipelago ·were converted Into land, the tropwal parts of the Indian Ocean would form a large and perfectly enclosed basin in which any great group of 1narine animals n1ight be ~ultipHed · and _here they would remain confined, until some of th~ speCies became adapted to a cooler climate, and were enabled to double the southern capes of Africa or Australia and thus reach other and distant seas. ' Frmn these and similar considerations but chiefly from our ignorance of the geology of other 'countries beyond the confines of Europe and the United States· and fro;n the revolution in our palreontological ideas on ~any hOJnts, which ~he discoveries of even the last dozen years ave e~ected, It seems to me to be about as rash in us to thgmatize on :he succession of organic beings throughout e world, as 1t would be for a naturalist to land for five |