﻿Animal Nature of Eozoon Canadense. 75- 



referred to Protozoa or to Hydrozoa, or, as seems more 

 likely, are divided between the two, they resemble Eozoon 

 in general structure and mode of accumulation of cal- 

 careous matter, and occupied a similar place in nature. 

 My own conclusion, in discussing the microscopic struc- 

 tures of the specimens of Eozoon, was that they were 

 probably those of Protozoa allied to those Foraminifera 

 with thick supplemental skeleton^ which had been 

 described by Dr. Carpenter. At the same time, I sus- 

 pected that those Stromatoporoids, like Coenostroma, 

 which possesses thick laminai penetrated by ramifying 

 tubes, might be allied to the Laurentian fossil. Dr. Car- 

 penter regarded the structures as combining in some 

 respects those of Eotaline and Nummuline Foraminifera,. 

 and ably, and as I think conclusively, defended this view 

 when attacked.^ The Eotaline type of Foraminifera has 

 since that time been traced by Cayeux and Matthew far 

 down into the pre-Cambrian rocks. The Nunnnuline 

 type is not known so early. As to the canal-bearing 

 Stromatoporoids, none of them show the fine tubulation, 

 though some have radiating and branching canals. Eecent 

 students of the Stromatoporae seem disposed to refer them 

 to Hydrozoa,^ a conclusion probable in the case of some 

 of the forms (especially those spinous ones incrusting 

 shells), but doubtful in the case of others, and more par- 

 ticularly the oldest of all, belonging to the genus Crypto- 

 zoon of Hall, and Archccozoon of Matthew,'^ the structure 

 of which seems, so far as known, to consist of very thin 

 primary laminae with a supplemental tubulated skeleton 

 resembling that of the genus Loftusia, and which must, 

 I think, be regarded as foraminiferal. In any case, 

 whether these primitive forms are Protozoa or rudimen- 

 tary Hydroids, they reach back in time nearly as far as 



1 Calcarina, etc 2 Ann. and Mag. Nat. Hist., loc. cit. 



3 Nicholson, Monographs Pal8eontograi)hical Society. 



4 Bulletin Nat. Hist. Survey of New Brunswick, 1894-95. 



