310 . Mr. H. J. Carter on the Structure of the Foraminifera. 



of Orhitolites, Orhiculina, Cycloclypeus, Heterostegina*, and Oper- 

 culina^, because they have enabled me most to correct, add to, 

 and explain what I have already stated respecting the Fora- 

 minifera, — it being easily conceived that, in a branch of know- 

 ledge like this, which is still in its infancy, every contribution 

 that is worth anything will probably more or less revolutionize 

 that which has preceded it, at the same time that it will claim 

 for its author that consideration for his errors and omissions 

 which such progressive knowledge demands. 



It might be asked, why I do not write complete editions of 

 my papers, instead of giving simply corrections, additions, &c. 

 My reply is, that I have not time to do this now, and therefore 

 record what I have to offer for the use of others for this purpose, 

 or for my own use on some future occasion, as the case may be. 



Needing then no other introduction than this, I will only 

 further premise (as much of what I have already stated has been 

 denied) that, in my paper of 1852 on the structure of Opercu- 

 lum arahica, to which was added an illustration of an infiltrated 

 Nummulite (N. acuta), showing that the canal-system was the 

 same in both, I observed that the former would " elucidate all 

 that has hitherto been stated of, and leave little to be added to, 

 the general structure of foraminifcrous shells, both recent and 

 fossil;" and I am glad to be able to add now (viz. ten years since 

 this observation and my description of the structure of Opercu- 

 lum were written), that I have not stated in either anything which 

 I wish to recall. Since then, however, Ehrenberg has confirmed 

 what I have described and illustrated respectively of the canal- 

 system in Operculina and Nummulites (viz. in Nummulites striata, 

 in 1855 £); and lately I have been able to repeat this myself 

 most satisfactorily in another of the Striata, viz. in N. Ramondi 

 (mihi), as I shall show hereafter. 



I would also mention here my regret that, in my paper on the 

 structure of Operculina arahica, I did not observe that Professor 

 Williamson had previously pointed out the existence of the 

 canal-system in part, viz. in the marginal cord of Nonionina §. 

 This arose from ignorance of the fact; for I never have been 

 able even up to this day to obtain the volume of the ' Trans- 

 actions of the Microscopical Society of London ' (1st ser. vol. iii.) 

 in which it was published ; while that on Faujasina, by the 

 same author, which points out the " intrascptal canals " of this 

 system, although read in 1851, was not published by that Society 

 until 1853 (2nd ser. vol. i.), that is, a year after my paper on 

 Operculina arahica appeared in the ( Annals and Magazine of 



* Phil. Trans, part i. p. 181, and part ii. p. 549, 1856. f lb. p. 1, 1859. 

 % Phil. Trans. 1859, p. 28. § Ibid. 



