Stromatoporoids nfw^o/Eozoon. 451 



Accordingly Eozoon canadense is a colonial Perforate 

 Foraniiniferan, each unit being a coiled shell of theNummu- 

 litid type. There are no alar prolongations as in Nummuliles *. 



Classification of»Sb'omatoporoids. 



Tiie current classification, that of Nicholson, is based on 

 the theory that Stromatoporoids are Hydrozoa^ and naturally 

 needs revision. My work is not sufficiently advanced to 

 enable me to make any otlier than a few general remarks. 



The first point to notice is that these ancient Foraminifera 

 are all colonial forms which frequently form massive blocks. 



Murchison and Lindstrom mention the thick strata, the 

 piUars, and huge balls composed mainly of Stromatopora 

 discoidea to be found at Gothland, and Dupont calls atten- 

 tion ' to the fact that these organisms enter largely into the 

 formation of the Devonian limestones of Belgium. The 

 Stromatoporoids and Eozoon were, in fact, reef-forming 

 Foraminifera. 



These colonies of Foraminifera represent a simpler type 

 than is found at present, when most of the Foraminifera exist 

 as separate individuals, though it is not improbable that some 

 of the larger modern Foraminifera may be true colonies, and 

 not merely individuals which have grown by extension of 

 single segments in vertical and horizontal directions. 



I believe Eozoon to be the ancestor of the Nummulitidse 

 and the Stromatoporoids to be the predecessors of some of the 

 spirilline, rotalian, and acervuline liotaliidffi. 



In fitting tliese primitive colonial Foraminifera into Brady's 

 system tiiey should be placed at the head of their respective 

 families, viz. Eozooninai in tiie Nummulitidse, and Stromato- 

 porinse and Labechiince in the Rotaliidae. The colonial habit 

 is not of the first importance from tlie systematic point of 

 view. It is the unit which gives the cluti to the affinities. 

 Certainly the unit of Eozoon is a Numniulitid and that of 

 Stromatopora Rotalian. In Beatricea 1 see central globular 

 Globi(/eriiia-\[ke chambers, but the general mode of growth 

 suggests the acervuline type common among the flotaliida\ 



Eozoon. Geological and Biological Implications. 



1 find that Eozoonal specimens from N.W. Scotland, from 

 Connemara, and from Central Europe (Prof. Giimbel) are 



* It may be pointed out, alar prolongations are only present in some 

 subfamilies of Nummulitidse, and not in all. 



