92 
B. NATURAL HISTORY. 
about the year 1827 (Petrefacta Germainae, I., p. 21), in the following 
words: — 
• “ Polyparium hemisphcericum s. subglobosum, e stratis solidis et fun- 
goso-porosis alternantibus contiguis 
The first species described was S. concentrica from the Devonani 
limestone of the Eifel: “ S. stratis concentricis infundibuliformis un - 
datis.” N 
Save that the author seems to have contemplated the object in an 
inverted position, and thus to have figured it, the description of this 
species will apply to a large proportion of the massive Stromatoporce 
that have been since observed. Accordingly we find that authors have 
been in the habit of referring to this species a wide range of distin¬ 
guishable forms from various different formations. 
In his remarks upon this species, Goldfuss says, it sometimes 
attains a diameter of several feet. The funnel-form layers fit into 
each other in such manner that the inner and upper gradually become 
smaller and flatter. . The outer are generally undulated. All together 
form, with their outcropping edges, the even, concentrically furrowed 
upper surface of the coral-body. With a magnifier one is able to dis¬ 
cover that the basis of the thicker beds is a complicated net-work, 
while the spongy intervening beds are composed of coarse interwoven 
fibres. 
At a later period (Pfetr. Germ. I., p. 215), the learned author pre¬ 
sented the results of his investigation of the various forms which he 
brought together under the name of Stromatopora polymorpha. He 
remarks that while the study of the former species had led him to as¬ 
sociate it with true corals, giving it a position between millepores and 
madrepores, his later studies led him to range Stromatopora under the 
sponges. S. polymorpha was described as being primarily a thin 
incrustation of spongy matter deposited upon a coral, shell, or other 
submarine body, preserving on its exterior all the inequalities of the sup¬ 
porting body. Upon this successive layers of similar matter were de¬ 
posited, until the organism assumed its destined form, and the primi¬ 
tive body dissolved away, leaving a cavity in its place. Partly through 
the inequalities of the primitive body, and partly through the unequal 
deposition of the successive spongy layers, the surface became tuber- 
