References
- Dr. Carpenter, we find, makes some slight referencee to two or three other points. What he states in connexion with the 16th does not apply to our arguments, which were against his quasi-alchymical explanation (see Intellectual Observer vii 290 290 & 294) of a number of untoward difficulties frequently presented by the “proper wall” and “canalsystem,” and which cannot be ignored in any criticism on these parts.
- Mr. H. J. Carter has delineated the walls and their extensions (“columns of condensed shell-substance”) of Orbitoides dispansa, with something like a prismatic structure Ann. Nat. His. viii 3 ser.pl. xvi. fig. 1 dwhich may be asbestine; or, possibly, from being fasciculated and divergent, it is due to the canal-system: if the former, the cse is the only one known to us, with the exception of the doubtful one represented by D'Archiac and Haime, of the asbestine structure having been published.
- We cannot bring ourselves to accept unconditionally the view that “the striæ are the lines of cleavage,” although a number of considerations could be urged in its favour: the close conformity in direction between the striæ and the adjoining tubulation seems to be relative, and therefore militating against it; while, on the other hand, the organic development of the asbestine structure (in other words prismatic) is supported by certain observations made by Dr. Carpenter, which show that in Opericulina arabica the tubules of the chamber-roofs are each in the centre of a prism (see Introduction to Foraminifera 256 256 xvii. fig. 8
- See Quart. Journ. Geol. Soc. xxi 63 63 Intellectual Observer, vol. x. pp. 294, 295, tinted pl. fig. 1 (upper part left-hand side); Popular Science Review, vol. iv. pl. xv. fig. 10.
- The entire section is represented in Proceedings Royal Irish Acad x xli. fig. 4.
- See Quarterly Journal Geol. Society xxii 196 196 pl. xiv fig. 4Proc. Royal Irish Acad. vol. x. pl. xliii. figs. 5, 6.
- Nature , iii 186 – 186 .
- According to our theory, stated elsewhere Quart. Journ. Geol. Soc. xxii 192 192 pl. xiv. fig. 2Proc. Roy. Irish Acad. vol. x. pl. xli. fig. 2, p. 315; Geol. Mag. Jan. 1872), the presence of calcite in the “nummuline wall” is the result of chemical action, effected by the agency of carbonated solutions, similar to what has taken place in the production of pseudomorphs consisting of calcite after a silacid mineral.
- Carpenter . Quart. Journ. Geol. Soc.2 , xxi 64 – 64 .
- For a full account of this section, and specimens of a similar character, the reader is referred to the Proceedings of the Royal Irish Academy x 532 532 534, 535, pl. 44. fig. 11; also id. new series, vol. i. p. 132.