A chart of the Rugose corals. — Sherzer. 275 
classified entirely with respect to their skeletal remains, without 
an}^ regard for the }et unknown affinities of the polyps which se- 
creted them. Modern deep-sea corals occur, belonging to the same 
species and growing within a few feet of each other, which if clas- 
sified with respect to their hard parts alone, would probabl}' be 
placed in separate genera. On the other hand we know that 
amongst the more highly organized forms of life differences, de- 
tected only with difficulty, characterize the skeletons of animals 
belonging to separate families. We fancy that if the Trumpet of 
the Resurrection reanimates the dusty fossils on the shelves of our 
museum cases there is surprise in store for many a potyp when he 
first gazes into the countenance of his supposed brother. 
This chart of the Rugosa was primarily prepared for the pur- 
pose of making a comparative stud}' of its genera. Reference has 
been made to all available literature and figures, and many speci- 
mens have been examined. An attempt has just been made to 
have it as accurate and complete as possible by sending out sev- 
eral dozen advance copies to palaeontologists of Europe and Amer- 
ica, with a request for additions and corrections. In this attempt 
we have been partially successful, and it is now published with the 
hope that it may prove of service in the laboratory for the deter- 
mination and separation of genera. It is designed to contain not 
simply the corals which the latest investigations would place in 
the list, but those which the student now finds referred to 
it, and about which he may desire ready information. Zit- 
tel's simplification of the elaborate classification of Dybowski 
has been followed as best suited to our purpose, and disturbed 
only by the introduction of a few new genera. It is evident from 
the internal structure that some of the genera are out of place. 
In his latest Manual of Palaeontology, Prof. H. A. Nicholson con- 
siders the group simply a Section of Madreporaria instead of a 
Sub-Order of Zoantharia as established by Edwards and Haime. 
He locates and divides the group as below : 
Order. Zoantharia. 
Sub-Order A. Actinaria. 
Sub-Order B. Antipatharla. 
Sub-Order C. .Madreporaria. 
Sec. i. M. Aporosa. 
Sec. n. M. Rugosa. 
