376 Mr. H. J. Carter on the 



LIT. — On the Structure called Eozoon canadense in the Lau- 

 rentian Limestone of Canada. By H. J. CaeteRj F.R.S. 

 &c. 



I SEE bj Dr. Carpenter's " Remarks " in the last number of 

 the ' Annals ' that, in my letter to Prof. King on the so-called 

 " ^02;oo/i canadense "(' Annals/ March 1874, xiii. p. 189), 

 I did not lay sufficient stress on the imrallelism of the acicular 

 structure loith the grains of serpentine. This is particularly 

 well shown in the illustrations 1, 2, 3, 5, 6, 9, and 10 of Profs. 

 King and Rowney's paper in the Transactions of the Royal 

 Irish Academy, vol. x. p. 506, from which I have taken 

 the liberty of causing to be copied fig. 1, pi. 1, which is repro- 

 duced in the following woodcut. 



From the " description " of 

 this figure, I learn that it 

 represents '' a portion of a 

 ' chamber-cast ' from a trans- 

 parent section of ' eozoonal ' 

 ophite from Canada, presented 

 to Dr. Rowney by Dr. Car- 

 penter, as seen by reflected light with a power magnifying 

 120 diameters." 



a is the portion of a ' chamber-cast,' c d the acicular struc- 

 ture or so-called '^ tubuli," " nummuline layer," or " nummu- 

 line tubulation," and h the serpentine seen through the latter. 



Now I can testify to this, as well as to all the other illus- 

 trations of the kind given in this paper, as being correct 

 instances of the parallelism of the acicular with the serpentine. 



Hence this character is utterly incompatible with foramini- 

 feral structure ; for the tubuli of the chambers of the testaceous 

 Foraminifera forming in juxtaposition a crust of columnar 

 tubes which keep up a direct communication between the 

 cavity of the chamber and the outer world, necessarily take 

 the siiortest course to produce this ; and that course is therefore 

 perpendicular to the surface or confines of the chamber and not 

 parallel to it — in other words, a " straight line." 



If there be any inclination, it is exceptional and not the rule ; 

 for Nature here, as in all other instances, is ever economic of 

 her means. 



Now what do we find in the so-called " eozoonal limestone"? 

 that the acicular structure, which has been stated to represent 

 the tubuli, is almost always ^:)a/*aZ/e/ to the serpentine, after the 

 manner shown in the illustration. 



Thus, if there be even only one instance where the parallel- 

 ism, can be demonstrated, it would show that the aciculje could 



