6 
calices are very distinctly represented side by side in the same chain, and 
following one of them a mesopore, also a corallite with rolling tabulae, or as 
Ludwig described them “ bow-shaped.” Twelve septa arc represented. 
1871. — Fischer- Benzon (II.). 1 — This author’s paper was the first real 
attempt to portray the more minute and detailed structure of Ralysites. 
After a long study of a very carefully prepared translation, I have come to 
the conclusion that from a systematic point of view too much importance 
cannot be attached to it, and as an exposition of the microscopic structure it 
stands before any other writing I have access to. Dr. Fischer-Benzon’s 
material appears to have been derived chiefly from diluvial boulders exhibiting 
little, if any, of the more important external features of the corallums, and 
from this cause it is, and will remain difficult, to assign his species to already 
known forms, even if it be found necessary to do so. 
In his generic description the author referred to — (1) the free chains; 2 
(2) the wrinkled epitheca ; (3) twelve or more delicate spiniform septa; 
(4) the distal ends of the latter sometimes blended into a spurious columella : 
(5) complete and incomplete tabulae of the autopores ; (6) tabulate nature of 
the mesopores (thus supporting Hall’s description of his Catenipora agglom- 
erata) possessing a dual structure — (a) saddle-shaped and lenticular vesicles, 
or (b) horizontal tabulae, enclosing small regular visceral chambers ; (7) com- 
plicated structure of the intermediate or mesoporal walls ; and (8) lateral 
gemmation. 
Fischer-Benzon adopted a classification of his species based on the 
structure of the mesopores and their walls ; and remarked, “ as nearly all the 
earlier figures of Ralysites are without accurate delineations of the dividing 
walls [of the corallites], and the peculiar calices are not enlarged, it is difficult 
to distinguish them from one another, specially so if one has no opportunity 
of investigating the original specimens.” This is perfectly true ; but the 
structural details employed by Fischer-Benzon appear to depend so much on 
the degrees of development and secondary alteration, that I am afraid his 
method of classification will not stand the test of future research. 
Fischer-Benzon regards the structure of the mesoporal walls, or those 
separating the mesopores from the autopores, as of great importance. He 
says, “The nature of these dividing walls seems to me the most certain means 
1 Fischer-Benzon, Abhandl. Gebiete Naturwis. Verein Hamburg, V, 2 Abth., 1871, p. 31 (separate copy), 
pis. iii. 
5 New chains with a free end projecting into a fenestrule. 
