BRITISH ASSOCIATION. 



255 



formed of the detritus of pre-existing rocks, and as there were not equal 

 conditions for producing and carrying that detritus, there would be 

 more striking deviations from the general rule in one place than another : 

 the deposits might have no representations at all in time ; therefore, to 

 say that one deposit was perfectly represented by another, would be 

 drawing conclusions without the necessary evidence. Both sections 

 and fossils were necessary ; but after all, we could only give names to re- 

 present the state of our knowledge ; facts much more numerous and much 

 stronger than those on which our divisions were founded, might compel 

 us to alter our names. The division of the older rocks into Carboniferous, 

 Devonian, and Silurian, should be retained as long as possible ; but 

 the moment we attained a sufficient body of evidence, we must modify 

 our views. The different value of names in different parts of the world, 

 rendered it useless to attempt to make American deposits square exactly 

 with our own ; our definition of carboniferous limestone would not apply 

 to Ireland ;* a fortiori, we could not expect it to coincide strictly with 

 America ; and lastly we should endeavour to make our nomenclature as 

 effective as possible, for distinguishing grouping formations in all parts 

 of the world, so as to make the terms comparable. 



Report on British Belemnites, by Mr. Phillips, 



Mr. Phillips stated that he had been called upon by the 

 Committee for a report on this subject ; he had prepared 

 drawings of some of the most characteristic forms, to which 

 he now desired to call attention, as this class of organic 

 remains had been greatly neglected, and he had experienced 

 considerable difficulty in procuring information on the 

 subject. M. Blainville had pointed out the analogy of struc- 

 ture they presented to certain bodies found in cuttle-fish, 

 and other analogies with the nautilus. Mr. Voltz and Dr. 

 Buckland had also investigated the subject, and pubfished 

 many important results. Mr. Philhps stated that he had 

 himself pubfished several forms of belemnites in his ^ Geo- 

 logy of Yorkshire,' but that until he had examined the 



* Why then, as carboniferous limestone (a general appellation) is not 

 generally apphcable, should Geologists have adopted a term to which 

 they do not assent }—Ed. Geologist. 



