512 



Dawson, "showing" the so-called canals 44 imperfectly infiltrated with 

 black (carbonaceous ?) matter." Looking at Dr. Dawson's figure 

 PI. XII., fig. 1), and his description, we shall be much deceived if the 

 " canals," such as they are delineated, be anything else than aggrega- 

 tions of the " minute grains and fibres of carbonaceous matter" belong- 

 ing to the " matrix" that have got entangled in the carbonate of lime 

 while crystallizing out in the presumed " septa," as is often seen 

 in minerals vitiated or rendered impure by foreign admixtures. 



Other objections might be urged — such as the fact of the so-called 

 " chambers" being filled with the same " dark stone," or mechanically 

 formed deposit, as the matrix— the implied admission that the " minute 

 veins of calcareous spar traversing the septa, and the cleavage planes, 

 which have been developed in some portions of the latter," are " crys- 

 tallized structures," that might "mislead any ordinary skilful micros- 

 eopist;" but the aforementioned are sufficient. Moreover, the "few 

 rare instances only," or "obscure" indications, of the "nummuline 

 layer," spoken of, have, we believe, been as much misunderstood as the 

 same part is in type specimens of " Eozoon Canadense." 



Closing for the present our remarks on the Tudor " fossil," we 

 may briefly suggest that it is nothing more than the result of in- 

 filtration of carbonate of lime, which has penetrated into a parting 

 between two layers of the laminated arenaceous limestone ; or it may 

 be an example of anastomosing strings of segregated calcite ; in short, 

 it may be anything consistent with the nature of its matrix } or the condi- 

 tions under which the latter has existed. 



Dr. Dawson has made an objection to our use of the term " eozoonal." 

 We are not aware of having gone beyond what has or would have been 

 done by others ; indeed, it could easily be shown that we are actually 

 behind Dr. Dawson himself in this respect. We described as " eozoonal" 

 certain ophites from Connemara, Donegal, India, Bavaria, the State 

 of Delaware, and the Isle of Skye ; and no valid reasons have been 

 offered to show that we were wrong, or even that we have strained the 

 meaning of the term. 



It is somewhat singular that Giimbel, who has used the term in a less 

 restricted sense than we have {but who believes in "Eozoon") has escaped 

 all adverse criticism. He is perfectly correct; for, in assuming " the 

 presence of Eozoon in the crystalline limestones of Finland," from the 

 fact of their containing " rounded, cylindrical, or tuberculated grains 

 of pargasite" — and that the " coccolite-bearing limestone of lew York 

 seems to be closely related" to them, and to the " Eozoon ophicalcite of 

 Steinhag"-— he is only carrying out the " received doctrine" to its 

 proper extent. 



"Eozoonal" rocks, we are certain, will turn out to be much more 

 common than may be conveniently admitted. Of late, specimens of 

 various kinds of ophite have fallen under our notice. We have ob- 

 tained examples, according to their labels, from "Egypt," " Nei- 

 biggen," "Italy," and "Scandinavia;" and, although differing more or 



