304 IMPERFECTION OF THE Chap. IX. 



any secondary formation, seemed fully to justify the 

 belief that this great and distinct order had been sud- 

 denly produced in the interval between the latest 

 secondary and earliest tertiary formation. But now we 

 may read in the Supplement to Lyell's ' Manual/ pub- 

 lished in 1858, clear evidence of the existence of whales 

 in the upper greensand, some time before the close of 

 the secondary period. 



I may give another instance, which from having 

 passed under my own eyes has much struck me. In a 

 memoir on Fossil Sessile Cirripedes, I have stated that, 

 from the number of existing and extinct tertiary species ; 

 from the extraordinary abundance of the individuals of 

 many species all over the world, from the Arctic regions 

 to the equator, inhabiting various zones of depths from 

 the upper tidal limits to 50 fathoms ; from the perfect 

 manner in which specimens are preserved in the oldest 

 tertiary beds ; from the ease with which even a frag- 

 ment of a valve can be recognised ; from all these cir- 

 cumstances, I inferred that had sessile cirripedes existed 

 during the secondary periods, they would certainly have 

 been preserved and discovered ; and as not one species 

 had been discovered in beds of this age, I concluded 

 that this great group had been suddenly developed at 

 the commencement of the tertiary series. This was a 

 sore trouble to me, adding as I thought one more in- 

 stance of the abrupt appearance of a great group of 

 species. But my work had hardly been published, when 

 a skilful palaeontologist, M. Bosquet, sent me a drawing 

 of a perfect specimen of an unmistakeable sessile cirri- 

 pede, which he had himself extracted from the chalk 

 of Belgium. And, as if to make the case as striking as 

 possible, this sessile cirripede was a Chthamalus, a very 

 common, large, and ubiquitous genus, of which not one 

 specimen has as yet been found even in any tertiary 



