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decayed cephalopodous family, I hope to show you that this is 

 not its true pedigree, that the straight orthoceras is not the 

 root of title. 



But the President has a right to say that he needed not to 

 ground his argument on the evidence of British rocks alone, 

 nor place it on so narrow a basis as the mere form of the shell. 

 This must be granted. Subsequently to the delivery of his lecture, 

 a most potent ally has come forward in the person of my friend 

 Professor Alpheus Hyatt, the Curator of the Natural History 

 Society of Boston, in Massachusetts, who has devoted all the 

 powers of an acute intellect, large experience, and ample 

 opportunity on both sides of the sea, to the investigation of 

 this very subject, and who has just published, in the 

 proceedings of the Boston Society, his adoption of evolu- 

 tionary views and of the theory of Professor Huxley. 

 Notwithstanding this, I will try to lay before you the reasons 

 which, in my judgment, are decisive against the conclusions 

 of these eminent men. In doing this, I shall have to trouble 

 you with some dry details of geological, or rather palasonto- 

 logical facts regarding the succession of rocks, and of the life 

 indicated by their fossil contents. 



We have first to speak of the shells. 



The nautilus is, as is well known, the sole living represen- 

 tative of a vast family of marine creatures, which floui'ished 

 in the first palseontological ages, and are known to us in a 

 fossil condition under various names. In the lowest strata the 

 form called orthoceras prevailed, though, as we have shown, 

 it does not appear first. In subsequent times the coiled 

 ammonite is the prevailing form. The latter is so numerous 

 in the rocks that its remains stand as the popular type of 

 fossil life in general. 



These creatures belong to the group of cephalopods, 

 the highest form of animal life existing in marine shells. 

 They derive their distinctive class-name from their having 

 the feet placed in a ring round the mouth. 



The commonest cephalopod now known to us is the cuttle- 

 fish, which has an internal calcareous support ; the most beau- 

 tiful, externally, is the pearly nautilus before referred to. 

 The nautilus has two pairs of gills, the cuttle-fish only one pair, 

 and the whole assemblage is divided into two families pos- 

 sessing this difference, — the one called the dibranchiates, the 

 other the tetrabranchiates. The former, the cuttle-fish kind, 

 are the most numerous in the present seas ; but in the ancient 

 oceans the nautiloids prevailed, and formed really the leading 

 feature in the life of the period, so far as we know. The 

 London clay immediately beneath where we now stand contains 



