54 PBOCEEDINGS OF THE GEOLOGICAL SOCIETY. [NoV. 23, 



The complicated systems of tubuli in the Laurentian fossils indi- 

 cate, however, a more complex structure than that of any of the 

 forms mentioned above. I have carefully compared these with the 

 similar structures in the " supplementary skeleton " (or the sheLl- 

 substance that carries the vascular system) of Calcarina and other 

 forms*, and can detect no difference except in the somewhat 

 coarser texture of the tubuli in the Laurentian specimens. It 

 accords well with the great dimensions of these, that they should 

 thus thicken their walls with an extensive deposit of tubulated cal- 

 careous matter ; and, from the frequency of the bundles of tubuli, as 

 well as the thickness of the partitions, I have no doubt all the suc- 

 cessive walls as they were formed were thickened in this manner, just 

 as in so many of the higher genera of more modern Foraminifera. 



It is proper to add that no spicules, or other structures indicating 

 affinity to the Sponges, have been detected in any of the specimens. 



As it is convenient to have a name to designate these forms, I 

 would propose that of Eozoon, which will be specially appropriate to 

 what seems to be the characteristic fossil of a group of rocks which 

 must now be named Eozoic rather than Azoic. For the species 

 above described, the specific name of Ganadense has been proposed. 

 It may be distinguished by the following characters : — 



EozooK Canadense, gen. et spec. nov. Pis. VI. & Yll.f 



General form. — Massive, in large sessile patches or irregular cylin- 

 ders, growing at the surface by the addition of successive laminae. 



Internal structure. — Chambers large, flattened, irregular, with 

 numerous rounded extensions, and separated by walls of variable 

 thickness, which are penetrated by septal orifices irregularly dis- 

 posed. Thicker parts of the walls with bundles of fine branching 

 tubuli. 



These characters refer specially to the specimens from Grenville 

 and the Calumet. There are others from Perth, Canada West, which 

 show more regular laminae, and in which the tubuli have not yet been 

 observed ; and a specimen from Burgess, Canada West, contains some 

 fragments of laminae which exhibit, on one side, a series of fine par- 

 allel tubuli like those of Nummulma. These specimens may indicate 

 distinct species ; but, on the other hand, their peculiarities may 

 depend on different states of preservation. 



With respect to this last point, it may be remarked that some of 

 the specimens from Grenville and the Calumet show the structures 

 of the laminae with nearly equal distinctness whether the chambers 

 have been filled with serpentine or pyroxene, and that even the minute 

 tubuli are penetrated and filled with these minerals. On the other 



* I desire to express my obligations to the invaluable memoirs of Dr. Carpenter 

 on the Foraminifera, in the ' Ti'ansaetions ' of the Royal Society and in the piib- 

 lications of the Hay Society, and without which it would have been impossible 

 satisfactorily to investigate the structure and affinities of Eozoon. I have also 

 to acknowledge the kindness of Dr. Carpenter in furnishing me with specimens 

 of some of the forms described in his works. 



t Plates VIII. & IX., illustrating the following paper by Dr. Carpenter, 

 further elucidate the structure of Eozoon. — Ed. 



