64 PEOCEEDmGS or THE GEOLOGICAL SOCIETY. [NoV. 23, 



It seems to me worthy of special notice, that the " canal-system," 

 wherever displayed in transparent sections, is distinguished by a 

 yellowish-brown coloration, so exactly resembling that which I 

 have observed in the canal-system of recent Foraminifera (as Poly- 

 stomella and Calcarina) in which there were remains of the sarcode- 

 body, that I cannot but believe the infiltrating mineral to have been 

 dyed by the remains of sarcode still existing in the canals of Eozoon 

 at the time of its consolidation. If this be the case, the preservation 

 of this colour seems to indicate that no considerable metamorphic 

 action has been exerted upon the rock in which this fossil occurs. 

 And I should draw the same inference from the fact that the organic 

 structure of the shell is in many instances even more completely 

 preserved than it usually is in the Nummulites and other Forami- 

 nifera of the Nummulitic limestone of the early Tertiaries. 



To sum up, — That the Eozoon finds its proper place in the Forami- 

 niferal series, I conceive to be conclusively proved by its accordance 

 with the great types of that series in all the essential characters of 

 organization, — namely, the structure of the shell forming the proper 

 wall of the chambers, in which it agrees precisely with Nummidina 

 and its allies ; the presence of an " intermediate skeleton " and an 

 elaborate " canal-system," the disposition of which reminds us most 

 of Calcarina ; a mode of communication of the chambers when they 

 are most completely separated, which has its exact parallel in Ci/clo- 

 clypeus ; and an ordinary want of completeness of separation between 

 the chambers, corresponding with that which is characteristic of 

 Catpenteria. 



There is no other group of the Animal Kingdom to which Eozoon 

 presents the slightest structural resemblance ; and to the suggestion 

 that it may have been of kin to Nidlipore I can offer the most distinct 

 negative reply, having many years ago carefully studied the stmcture 

 of that stony Alga, with which that of Eozoon has nothing whatever 

 in common. 



The objections which not unnaturally occur to those familiar with 

 only the ordinary forms of Foraminifera, as to the admission of 

 Eozoon into the series, do not appear to me of any force. These 

 have reference in the first place to the great size of the organism ; 

 and in the second, to its exceptional mode of growtli. 



1. It must be borne in mind that all the Foraminifera normally 

 increase by the continuous gemmation of new segments from those 

 previously formed; and that we have, in the existing types, the 

 greatest diversities in the extent to which this gemmation may pro- 

 ceed. Thus in the Olohigerina;, whose shells cover to an unknown 

 thickness the sea-bottom of all that portion of the Atlantic Ocean 

 which is traversed by the Gulf-stream, otAj eight or ten segments are 

 ordinarily produced by continuous gemmation ; and if new segments 

 are developed from the last of these, they detach themselves so as to 

 lay the foundation of independent Glohigerince. On the other hand, 

 in Cydoclgpeus, which is a discoidal structure attaining 2\ inches in 

 diameter, the number of segments formed by continuous gemmation 

 must be many thousand. Again, the Receptac^dites of the Canadian 



