214 | Scientific Intelligence. 
(21.) The occurrence of “ eozoonal features ” solely in crystalline 
or metamorphosed rocks, belonging to the Laurentian, the Lower 
Silurian, and the Liassic systems—never in ordinary unaltered 
deposits of these and the intermediate systems—must be assumed 
as completely demonstrating their purely mineral origin. 
g apt. 
The reading of the foregoing paper was followed by a short 
communication from Dr. Dawson, on “two points,” which it is now 
necessary to notice :— 
The authors add to the paper the following postseri 
i ol 
&e. The case esting : , ne 
established fact that foraminiferal shells, corals, and other 
organisms occur with siliceous in-fillings of the kind—and having 
and some othe ade known last year by Dr enter) into 
the present discussion sides, it is altogether gratuitous, 
Inconsistent with scientific reasoning, to assume that the crinoidal 
in-filling “is similar to that effected by the ancient serpentine of 
the Laurentian” (Dawson) ; or, that it is “allied in the mode of 
n 
essential “ eozoonal feature” in connexion with a crystal of spinel, 
from ity. We now learn that Dr. Dawson has had under ex- 
anadense.” the inference that the specimens “ are po™ 
tions of a bedded rock, and not a vein stone ”--without taking 
into consideration that it is suppositional, and based on an examil 
natio specimens preserved tn collections—it cannot set aside 
i 
the plain fact, that in our specimen arborescent configurations— 
formed of groups of decreted erystals of malacolite, and identical 
takes refuge under the ad captandum argument, that its ‘ caleareous | ele 
(‘intermediate skeleton ”) “ show less departure from the shelly texture pire 
grea ij i le a. 
rocks of any geological period” (Natwe, No. 62); forgetting that, as the sub- 
Stance of such fossils has undergone so much cha 4 
aa eee 4 pl . ‘ ert +} 1 containing them—“ least altered had 
they may be—into the “highly crystalline condition” of “ eozoonal ” ophite. 
But Dr. Carpenter seems to misunderstand the objection altogether; as it is nt 
based so much on the mineral structure of the “ fe 
aed occur best preserved in “ highly crystalline ” or metamo 
er; 
1 features,” as on the fact 
rphosed an. 
