548 



and were it necessary to represent the latter, our representations would 

 be close facsimiles of the figures, already referred to, which Dawson, 

 Carpenter, and Rupert Jones, have published in their respective 

 memoirs. 



All the calcite of the specimen equally shows the same " eozoonal" 

 structures ; and that they have originated from the waste of crystals of 

 malacolite. One example consists of a prismatic or longitudinalfy- 

 cleaved mass of this mineral, having at one end the cleavage prisms 

 diverging, losing their edges, and slightly branching ; strikingly 

 resembling the case figured in our first memoir,* and reminding us 

 of the example of the " canal system," described by Dr. Carpenter as 

 " consisting of parallel lamellae disposed like the leaves of a book."f 



Since it was first announced that we had determined " Eozoon 

 Canadense v to be nothing more than a mineral production, we have all 

 along felt that specimens would be found demonstrating more and more 

 completely the truth of our conclusion: but we were certainly not 

 prepared to meet with a large crystal of spinel, holding in its chinks 

 and cavities typical examples of two of the essential features of this 

 reputed organism ; and these themselves possessing evidences indis- 

 putably testifying to their purely crystalline origin. 



The Aker and Amity specimens show, what we have long sus- 

 pected, as intimated here and there in the preceding Paper, that the 

 arborescent forms (" canal system") may consist of other silicates be- 

 sides serpentine. As to their being composed of anything else than a 

 siliceous substance, we are not yet prepared to offer an opinion on the 

 matter ; though it must not be overlooked that similar forms, but on a 

 comparatively gigantic scale, are common, consisting of carbonate of 

 lime, in magnesian limestone, near Sunderland, in Durham. We have 

 been led into this subject from observing a recent announcement, by 

 Dr. S terry Hunt, of another discovery in " Eozoon Canadense" (atChelms- 

 ford, near Lowell, IT. S.) of "the canals and tubnli of the calcareous 

 skeleton filled, not with a silicate, but with carbonate of lime." J On 

 seeing this announcement, we immediately wrote to Mr. Bicknell, of 

 Salem, mentioned by Dr. Sterry Hunt, asking him to oblige us with speci- 

 mens of the kind. Shortly afterwards we received from Mr. Bicknell, 

 by sample post, a transparent section carefully prepared by himself, and a 

 piece of the rock, — both labelled "Chelmsford." There were also speci- 

 mens of " eozoonal" ophite from Newberryport, a neighbouring locality. 

 In the latter, some of the structures are typically exhibited : the fibres of 

 the "nummuline layer,'' however, aremore confusedly arranged, and much 

 longer than usual. In the former, the serpentine, of a pale-greenish colour, 

 is in irregularly fractured pieces, separated from one another by unusu- 

 ally wide interspaces of calcite (" calcareous skeleton"), which contains 



* " Quarterly Journal of Geological Society," vol. xxii., PL XV",, fig. 17, b. 



f "Intellectual Observer," vol. vii., p. 294. 



X "Scientific Opinion," January 20, 1870, p. 45. 



