68 Dr. W. B. Carpenter on the Shell-structure of 



descends from the neck to the ventral fins. The brown portion 

 of the body coarsely reticulated with yellowish, the lines de- 

 scending from the back to the belly. Caudal tin and a cuneiform 

 band along the hinder half of the base of the dorsal yellow. 

 North-west coast of Australia (l)uboulay). 



IX. — On the Shell-structure of Spirifer cuspidatus, and of certain 

 allied Spiriferidse. By William B. Carpenter, M.D., 

 F.R.S. 



To the Editors of the Annals of Natural History. 



Gentlemen, 



Being now in a condition to give a complete and explicit 

 reply to the question raised by Mr. Meek, on which I addressed 

 you six months ago (Ann. Nat. Hist. Jan. 1867, p. 29), I take 

 the earliest opportunity of communicating to you the results of 

 my researches, which will be found, if I mistake not, of singular 

 interest to such palaeontologists as pay special attention to the 

 Brachiopoda. 



I think it due both to Mr. Meek and to myself to point out 

 that the note in the * Annals ' for August,^ 1866 (p. 144), in 

 which he is represented as calling in question the accuracy of 

 my original observations on the imperforate structure of the 

 shell of Spirifer cuspidatus, did not correctly express his views. 

 In a letter with which he favoured me immediately on reading 

 ray previous communication he says : — 



"I am sorry you had not seen my little paper before you 

 read the notice of it to which you allude. If you had done so, 

 I am sure you would have at once seen that I made no attempt 

 whatever to cast doubts upon the accuracy of your investiga- 

 tions. I never for a moment questioned the fact that the shells 

 examined by you are not punctate. The only question with me, 

 after seeing, as I believed, very minute and very scattering 

 punctures in the shells I had examined, was, whether there might 

 not be in Ireland, and possibly in England, another rare type, 

 not seen by you, indistinguishable by form and other external 

 characters from .S. cuspidatus, and yet widely separated by 

 having a punctate structure. Believing that this might be the 

 case, and knowing that, if so, it would be a matter of some in- 

 terest to know which was the true cuspidatus, I published my 

 remarks mainly in order to cause further investigations. 



"^'As you have doubtless ere this seen my little paper, you 

 must have observed that the words ' contrary to the opniion of 

 Dr. Carpenter,^ quoted by you, do not occur in it, nor any others 



