Sir W. JDauson — The Animal Nature of Eozobn. 549 



a character little likely to preserve organic marine forms of the 

 " benthos " or ground-living group. We might thus expect a gap 

 in our record between the fauna of the Grenville Series and that of 

 the next fossiliferous formations. 



Logan naturally compared his earlier specimens with the Stromato- 

 porae so abundant in the Ordovician and Silurian Limestones ; and 

 in this he was justified, for, whatever may be the ultimate judgment 

 of naturalists as to these problematical fossils, and whether they are 

 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 calcareous matter, and occupied a 

 similar place in nature. My own conclusion, on discussing the 

 microscopic structures of the specimens of Eozoon, was that they 

 were probably those of Protozoa allied to those Foraminifera with 

 thick suppleuiental skeleton ^ which had been described by Dr. 

 Carpenter. At the same time, 1 suspected that those Stromatoporoids, 

 like Coenostroma, which possess thick laminae penetrated by rami- 

 fying tubes, might be allied to the Laurentian fossil. Dr. Carpenter 

 regarded the structures as combining in some respects those of 

 Eotaline and Nummuline Forauiinifera, and ably, and as 1 think 

 conclusively, defended this view when attacked.^ The Rotaline 

 type of Foraminifera has since that time been traced by Cayeux and 

 Matthew far down into the pre-Cambrian rocks. The Nummuline 

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

 poroids, none of them show the fine tubulation, though some have 

 radiating and branching canals. Eecent students of the Stromato- 

 pora 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 

 particularly the oldest of all, belonging to the genus Cryptozoon of 

 Hall, and Archeeozoon of Matthew,* the structure of which seems, 

 so far as known, to consist of very thin primary laminas with 

 a supplemental tubulated skeleton resembling that of the genus 

 Loftmia, and which must, I think, be regarded as foraminiferal. In 

 any case, whether these primitive forms are Protozoa or rudimentary 

 Hydroids, they reach back in time nearly as far as Eozoon, and are 

 equally massive and abundant, and may be regarded as analogous to 

 it in magnitude, habitat, mode of growth, and function in nature. 



These later discoveries are gradually widening the hoi'izon of 

 palaeontologists in the direction of the dawn of life, and the studies 

 of those who trace backward the history of the Invertebrates of the 

 Palasozoic seas are demanding more and more the discover^' of 

 earlier forms than those yet known to complete the chain of life.^ 

 The field is a difficult one to cultivate, and demands both labour and 

 patience, but it holds forth the prospect of great discoveries, and it 

 has already become the duty and interest of palasontologists to 



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



^ Nicholson, Monographs Palaeontographical Society. 



* Bulletin Nat. Hist. Survey of New Brunswick, 1894-5. 



* See Dr. Woodward's Addi'ess as President of the Geological Society, 1895. 



