542 



It would be a marvel to find a Liassic ophite possessing characters 

 strictly identical with those typical of " JSozoon Canadense ;" still the 

 similarity is surprisingly close. If anything is to he " admitted," it is 

 that the rock, as far as we have ascertained, " fails" in having the 

 "canal system" so remarkably arborescent as it is in the much older 

 ophites. Nevertheless, this feature is well represented by the " thickish 

 dendritic aggregations," also by some other forms we have lately 

 detected strictly identical with the "small" and common variety repre- 

 sented by Dr. Carpenter in his original memoir."* The "nummuline 

 layer," too, is a strictly identical " essential point;" but, owing to the 

 "chamber casts" consisting of a very pale green serpentine, in some 

 cases translucent and nearly colourless, the aciculi do not present that 

 striking contrast to the former so beautifully displayed in typical 

 examples. f 



One of the arguments we advanced against the organic origin of 

 " Eozoon" was based on the fact that this " fossil," although occurring 

 in various geological systems, had not been found except in metamorphia 

 rocks. The way the Tudor specimen (also the " mere fragments" 

 already noticed) was ushered into public notice was calculated to 

 induce the belief that it had been discovered in an ordinary unal- 

 tered calcareous deposit. Thus, — "a remarkable specimen of Moscow 

 Canadense has lately been found in Laurentian limestone" ("homo- 

 geneous"), " establishing the conclusion previously arrived at from the 

 study of remains of Eozoon included in serpentinous rocks" (Carpenter). 

 Other accounts, however, describe the matrix as a " dark-coloured, 

 laminated limestone, holding sand, scales of mica, and minute grains 

 and fibres of carbonaceous matter" (Dawson), — a "blackish argillaceous 

 limestone" ("calcaire argileux et noiratre," Sterry Hunt),— a "mica- 

 ceous limestone or calc schist" (Logan and Yennor), — a rock " compara- 

 tively unaltered" (Logan) — "not so much altered as those near Gren- 

 ville" (Smyth). Thus, after all, the Tudor specimen — whatever its 

 matrix may turn out to be — occurred in a metamorphic deposit; it 

 being from a " region in which the Laurentian rocks of Canada appear 

 to be less highly metamorphosed than is usual" (Dawson).]; We hold 



* " Quarterly Journal of Geological Society," vol. xxi., PI. VIII., fig. 5. 



f We have not yet succeeded in obtaining specimens of " eozoonal" ophite from 

 undoubtedly later geological periods than the Liassic ; but from what we perceive in 

 specimens of serpentine rock, without any lime, considered to be Miocene, from Italy, and 

 kindly presented to us by the Chevalier Jervis of Turin, also others, containing lime, 

 some stated to be Italian, for which we are indebted to the firms of Edmondson & Co., 

 and Sibthorpe & Son, of Dublin, and those already noticed exposed in the Paris Ex- 

 hibition and the Jardin des Plantes, we entertain a strong suspicion that the Tertiary 

 " ophicalcite" of that country will prove to be " eozoonal." A specimen of ophite from 

 "Egypt" in our possession, also possibly Tertiary, contains grains and lumps of 

 serpentine, imbedded in calcite : the latter mineral is crowded with very long parallel 

 aciculi, both separated and juxtaposed. 



% The mineral origin of the Tudor specimen is in no way invalidated by the fact of 

 its matrix being " comparatively unaltered;" as it is not a rare circumstance for slightly 



