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



cell-contents of Spirogyra, and in its sporangia produces the 

 monociliated spores mentioned, which, in 1857, I described as 

 furnishing an instance of the " transformation of the vegetable 

 protoplasm into Actinophrys*," forsaking my original argument 

 that these products must be parasitical, which Pringsheim's dis- 

 coveries have now confirmed -j\ 



Besides the course which the spherules have for their exit 

 through the canal-system, some of my recent specimens present 

 a hole here and there at the base of the few last chambers, oppo- 

 site the great spiral canal, in which holes the large spherules, 

 now white, may be seen, as if in the act of being voided, and 

 probably from the great spiral canal. A single large hole, with 

 a smooth margin, evidently formed by the animal itself, also ap- 

 pears here and there, sometimes, in the side of the chambers; 

 and this may have been for the purpose of giving exit to young 

 Operculince which had become too large to obtain their issue in 

 the ordinary way, such as those noticed by Prof. Schultze in the 

 Rotalida (Ann. Nat. Hist, vol.vii. p. 306, 1861) and also by Dr. 

 S. Wright (ib. vol. vii. p. 357). But both these kinds of holes 

 must be regarded as accidental, and not as regular developments 

 of the test. 



NUMMULITES. 



The structure of the test of Nummuliles is precisely that of 

 Operculina, plus the lateral or vertical growth of the former, 

 which is but a repetition, in plan, of the horizontal plane. Of 

 this I was aware in 185.2, when my description of the structure 

 of Operculina was published, and my diagram of an infiltrated 

 specimen of N. acuta (Ann. Nat. Hist. /. c), to confirm this, ac- 

 companied it. Since then, as before stated, the " canal-system " 

 has been figured by Ehrenberg from an infiltrated specimen of 

 N. striata; and within the last twelve months I have been able 

 to see everything which I have described in the test of Operculina 

 exemplified in richly infiltrated specimens of another of the 

 Striata, viz. N. Ramondi, accompanied by equally richly in- 

 filtrated specimens of Operculina ; so that the means of identifi- 

 cation has, through the latter, been most satisfactory. 



Canal-system, — The lateral or vertical development of Num.- 

 mulites being the only additional part to the horizontal plane as 

 it exists in Operculina, I have merely to state concerning the 

 canal-system of this, that radiating branches are continued up- 

 ward towards the centre or umbilicus of the Nummulite from 

 the great "spiral" canals of the cord, or from others near 

 this, along each intcrseptal space, and from each turn of the 



* Ann. Nat. Hist. ser. 2. vol. xix. p. 259. 



f Ann. lies Sc. Nat. xi. p. 349, pi. 7, Bot. 1S59. 



