1867.] DAWSOJS^ — LAUEEITTIAN FOSSIIS, 259 



places (PL XII. fig. 1), however, these appear as distinct bundles, 

 similar to those in the GrenviUe specimens, but of fine texture. 



[In fig. 2 is represented a portion of the canal-system in a GrenviUe 

 specimen, in which the canals, which are transparent in one side 

 (being infiltrated with carbonate of lime only) are seen on the other 

 to be partially fiUed with black matter, probably a carbonaceous 

 residuum of the sarcode which they originally contained. — W.B.C.] 



In a few rare instances only, can I detect, with a higher power, 

 in the margin of some of the septa, traces of the fine tubulation 

 characteristic of the proper chamber-wall of Eozoon. Por the most 

 part this seems to have been obliterated by the infiltration of the 

 tubuli with colourless carbonate of lime, similar to that of the 

 skeleton. 



In comparing the structure of this specimen with that of those 

 found elsewhere, it would appear that the chambers are more con- 

 tinuous, and wider in proportion to the thickness of the septa, and 

 that the canal-system is more delicate and indistinct than usual. In 

 the two former respects the specimens from the Calumet and from 

 Burgess approach that now under consideration more nearly than 

 do those from GrenviUe and Petite IS'ation ; but it would be easy, 

 even in the latter, to find occasional instances of a proportion of 

 parts similar to that in the present example. General form is of 

 little value as a character in such organisms ; and, so far as can 

 be ascertained, this may have been the same in the present specimen 

 and in that originaUy obtained from the Calumet, whUe in the spe- 

 cimens from GrenviUe a massive and aggregative mode of growth 

 seems to have obliterated all distinctness of individual shape. With- 

 out additional specimens, and in the case of creatures so variable 

 as the Foraminifera, it would be rash to decide whether the differ- 

 ences above noticed are of specific value, or depend on age, variability, 

 or state of preservation. Por this reason I refer the specimen for 

 the present to Eozoon Canadense, merely distinguishing it as the 

 Tudor variety. 



Prom the state of preservation of the fossU, there are no crystaUine 

 structures present which can mislead any ordinarUy skilful micro- 

 scopist, except the minute veins of calcareous spar traversing the 

 septa, and the cleavage-planes which have been developed in some 

 portions of the latter. 



I would remark that, as it seemed desirable not to injure any 

 more than was absolutely necessary a unique and very valuable 

 specimen, my observations of the microscopic structure have been 

 made on a few sUces of smaU size, — and that, as the microscopic 

 structures are nearly the same in kind with those of specimens 

 figured in former papers, I have not thought it necessary to prepare 

 numerous drawings of them ; whUe the admirable photograph exe- 

 cuted for Sir W. E. Logan by Mr. jS'orman Ulustrates sufficiently the 

 general form and arrangement of parts (see PL XI.). 



3. Concluding Remarks. — In a letter to Dr. Carpenter, quoted by 

 him in the ' Quarterly Journal of the Geological Society ' for August 

 1866, p. 228, 1 referred to the occurrence of Eozoon preserved simply 



