Dr. W. B. Carpenter on the Structure of Brachiopod Shells. 505 



draw them, when they shall be proved to have been premature ; 

 but until the structure of the species now in question shall have 

 been fully investigated, I must claim a suspension of the verdict. 



Prof. King attempts to justify his scepticism as to my former 

 statement of the non-perforation of certain Brachiopods, on the 

 plea that " fossilization had so obliterated the tissue of many 

 shells, as to render the detection of it an impossibility ; and it 

 was also conceived, that some shells were more prone than others 

 to become thus altered.^' This argument is, of course, quite 

 inapplicable to the case of Rh. psittacea, which I had described 

 as the type of the non-perforated group. Further, it will be 

 seen on reference to pars. 36 and 44 of my "Report'^ for 1844, 

 that I distinctly recognized the existence of this metamorphic 

 action as obscuring the structure of certain shells of this group ; 

 and I have never spoken confidently about the presence or 

 absence of perforations, save where the intimate structure of the 

 shell was so perfectly preserved as to leave no possible doubt 

 about the matter. Where the place of the passages which exist 

 in Prof. King's imagination is found to be occupied, not by fos- 

 silizing or metamorphic substance, but by the peculiarly charac- 

 teristic structure of the Brachiopod shell, I venture to affirm 

 that there can be " no mistake.^' 



The greater part of Prof. King's note, however, seems in- 

 tended to turn the tables upon me, by showing that my original 

 account of that structure was so incorrect, as tested even by 

 my own subsequent description of it, that no confidence what- 

 ever was to be placed in it ; and also, to claim for himself the 

 merit of setting me right. I shall not occupy your space by a 

 detailed justification of myself as to this matter, but shall simply 

 draw attention to the following points. 



In my original " Report '^ I did not minutely describe the 

 peculiar microscopic appearances of these Brachiopod shells, 

 considering that my figures spoke for themselves; but the 

 special object of that " Report " being to establish the organic 

 structure of Shell, I ofi'ered an interpretation of them (based on 

 the idea of plications in the shell-membrane), which at that 

 time seemed to me to be borne out by the facts I had ascer- 

 tained by the decalcification of recent shells and examination of 

 the organic residue. Subsequent examination having led me to 

 doubt the validity of this interpretation, I did not reproduce it 

 in my " Memoir " of 1854, but confined myself to a description 

 of the appearances^ which will be found to be accordant in all 

 essential particulars with my figures of 1844. As I never saw 

 the Memoir of Vicomte D'Archiac referred to by Prof. King, it 

 is not to that accomplished palaeontologist that my abandonment 

 of my former heresy is attributable. And that Prof. King has 



