No. 2.] DAWSON — EOZOON CANADENSE. 105 



Britain, is represented by a jaw-foot found in tlie Upper Lland- 

 overy sandstone, which is somewhat older than the Niagara 

 limestone. It has been named P. problematicus, and fragments 

 referred to the same species have been found in the Wenlock 

 limestone, the English representative of the Niagara. 



This note is published merely to secure to the discoverer, who 

 has laboured with much diligence and success in the palaeontology 

 of the Niagara formation, the credit which belongs to him, and 

 to direct attention to this interesting fossil, which it is hoped 

 may some day be represented in our collection by perfect speci- 

 mens. 



J. W. Dawson. 



March 20th, 1879. 



MOBIUS ON EOZOON CANADENSE.* 



By J. W. Dawson, LL.D., F.R.S. 



Eozoon Canadense has, since the first announcement of its 

 discovery by Logan in 1859, attracted much attention, and has 

 been very thoroughly investigated and discussed, and at present 

 its organic character is generally admitted. Still its claims are 

 ever and anon disputed, and as fast as one opponent is disposed 

 of, another appears. This is in great part due to the fact that 

 so few scientific men are in a position fully to appreciate the 

 evidence respecting it. Geologists and mineralogists look upon 

 it with suspicion, partly on account of the great age and crys- 

 talline structure of the rocks in which it occurs, partly because 

 it is associated with the protean and disputed mineral Serpentine, 

 which some regard as eruptive, some as metamorphic, some as 

 pseudomorphic, while few have had enough experience to enable 

 them to understand the difference between those serpentines 

 which occur in limestones, and in such relations as to prove their 

 contemporaneous deposition, and those which may have resulted 

 from the hydration of olivine or similar changes. Only a few 

 also have learned that Eozoon is only sometimes associated with 



* Dcr Bail dcs Eozoon Canadfiise, von Karl Mohiiis, Professor der 

 Zoologie in Kiel. Palaeoutographica, Band xxv. 



