30 On the Perforation of the Shell of Spirifer cuspidatus, 



I pointed out that the Sp. cuspidatus of the Mountain Limestone 

 differs from Sp. Walcotii and other Liassic Spirifers in not being 

 perforated, — the absence of the superficial punctations seen upon 

 the latter not being due (as Prof. Morris had supposed) to the 

 metamorphic condition of the shell, " since, although the struc- 

 ture of the shell is often obscured by this action, I possess sec- 

 tions in which it is extremely well preserved, and in which there 

 is an evident absence of the perforations.' ' 



The distinction which I thus drew between the two groups of 

 Spirifers characterized respectively by the perforation and non- 

 perforation of their shells, led Mr. Davidson to a more careful 

 examination of the internal structure which they respectively 

 present ; and the differences which he then discovered were such 

 as to lead him to separate these two groups generically, the 

 designation Spirifera being retained for the original Sp. striata, 

 cuspidata, and other imperforate species, whilst the perforated 

 species were remitted to the genus Spiriferina, 



The question as to the real character of Sp. cuspidata having 

 thus come to be of no small importance, I have gladly responded 

 to the suggestion of Mr. Davidson that I should re-investigate 

 it ; and I have commenced with a careful examination of my 

 original Bristol sections. These, I again confidently affirm, 

 show not the slightest trace of perforations, though the structure 

 of the shell is well preserved. 



I have obtained from the School of Mines, through Mr. 

 Etheridge, and from the Museum of Irish Industry and that of 

 the Geological Survey of Ireland, through Mr.W. H.Baily, chips 

 of specimens from six different localities, all which specimens 

 are vouched for by those gentlemen as genuine Sp. cuspidata. 

 In not one of the sections I have made of these shells is there 

 the smallest trace of perforations, though the structure of the 

 shell is well preserved in every instance. 



Further, at the suggestion of Mr. Davidson, I have examined 

 chips from the shells of the following Carboniferous species, all 

 of them more or less nearly allied to Sp. cuspidata : viz., Sp. laminosa 

 and Sp. distans, procured for me by Mr. Etheridge from the 

 Museum of the School of Mines; and Sp. suhconica, kindly 

 transmitted by Mr. Carrington from Derbyshire. These, like 

 Sp. cuspidata, show no trace whatever of perforations. 



I cannot but believe, therefore, that my original determination 

 of the imperforate character of the shell of Spirifera cuspidata 

 remains unshaken by Mr. Meek's contradiction ; and I can only 

 suppose either that Mr. Meek (like Prof. King*) has mistaken 

 the accidental black points which often present themselves on 



* See his ' Permian Fossils of England/ pp. 124, 125, and p. 110, note. 



