354 - On Eozoin Canadense. 
great thickening which the calcareous zones often present in ver- 
tical sections of Kozotin. The presence of this intermediate skel- 
eton has been correctly indicated by Dr. Dawson; but he does 
not seem to have clearly differentiated it from the proper wall of 
the chambers. All the tubuli which he has described belong to 
that canal-system which, as I have shown, is limited in its dis- 
tribution to the intermediate skeleton, and is expressly destined 
to supply a channel for its nutrition and augmentation. Of this 
canal-system, which presents most remarkable varieties in dimen- 
sions and distribution, we learn more from the casts presented by 
decalcified specimens, than from sections, which only exhibit 
such parts of it as their plane may happen to traverse.” « 
“Tt does not appear to me that the ‘canal-system’ takes its orl- 
gin directly from the cavity of the chambers. On the contrary, 
T believe that, as in Calcarina (which Dr. Dawson has correctly 
referred to as presenting the nearest parallel to it among recent 
Foraminifera), they originate in lacunar spaces on the outside of 
the proper walls of the chambers, into which the tubuli of those 
walls open externally; and that the extensions of the sarcode- 
body which occupied them were formed by the coalescence 0 
the pseudopodia issuing from those tubuli.” 
We have here a dia- 
gram by Dr. Carpen- 
val 
Ws 
ual Observer extract the | 
following remarks: It ui | fl 
will be understood that __ilji// SW 
, When 
the calcareous skeleton 
1s removed by an acid, 
af fe 
4. Diagram illustrating the structure of Hoz0dn. 
remains, and Dr. Car ee ee 
enter especiall. i A’, Al, Al, Three chambers of one layer, . 
lehe marvel = Sag nicating with each other directly at a, and by 
ees # three passages through a shelly partition at 0. 
pleteness: With which A2, A2, A2. Three chambers of a more su 
the minutest extensicr ayer. 
of the sareod, wate _ B, BR. Proper wall of the chambers, composed of 
<— “ en ay of finely tubular sbell-substance. 
the animal are repre- C, ©, C. Intermediate or supplemental arse 
 ~Ssen in- ‘alcified traversed by D, a stolon of tigre bg 
im: a Re : i ayers, : 
Specimens by these ser- tween two —— os different ay ts is 
pentine models: even oo gomopel ae baci 
