206 



8 



In the main I follow Zittel^) and Vaughan^) for the skeleton and anatomy of the 

 corals. Only at a very few points does the material at hand differ from the customary. The 

 determination of Columella, however, is worthy of note. This formation is classified by 

 various scientists as Columella proper and pseudo-Columella. Columella proper is supposed 

 to originate from a formation deposited in the kernel of the coral at the earliest stages of the 

 latter's development, and to have developed parallel with this in the direction of the calyx. 

 Columella proper may be divided according to its appearance into: 1) Styliform C. formed 

 by a massive column of lime; 2) lamella-like C. formed from a lamella-like hme plate on 

 which the costae find support, and 3) fasciculata C. formed by a group of twisted or folia- 

 ceous columns of lime. 



Pseudo-columella is the name given to those formed by the inner edges of the 

 septa, which in some way or other unite in the center of the coral. This junction of the septal 

 edges might lead to the formation of spongiose or tortile columella. 



Vaughan makes a distinction between lamella-like columella and columella proper, 

 demonstrating that the first is formed by a single septum which sends a leaf-like extension 

 towards the center on which the other septal edges find their support. 



The Danish material which shows such a septum, (Sphenotrochus granulatus, tab. 1, 

 figs. 24 — 25) wholly supports this view. Cutting shows that columella is a continuation of 

 a septal edge, and as the lowest portion of the coral has no columella, it cannot be an inde- 

 pendent formation branching out of the base of the coral. 



Styliform C. is found nowhere in the Danish material. 



Fasciculate C. is supposed to be found in certain of the species described: Caryo- 

 phyllia danica, Brachycyathus parvus and others, but the material is so small that it was 

 impossible to sacrifice any of it to cutting. 



In all the other species among which columella is found, and where, according to the 

 theories of the earlier authors, there should be a fasciculate C, i. e. an independent formation 

 projecting from the base of the coral, a pseudo-columella only seems to exist. This is not 

 located at the base of the coral, but is formed during the growth of the animal by the inner 

 edges of the septa curving from side to side in many folds. The curves of the adjacent septa 

 overlap and grow together forming a spongy mass with very regular folds and channels of 

 communication. This columella increases in thickness towards the top. It can attain very 

 considerable dimensions and projects from the bottom of the calyx. 



Forms like Coelosmilia and Smiloirochus, which authorities claim are entirely devoid 

 of columella, have a growth on their lower portions, though not the very lowest, resembhng 

 a columella formation, indistinguishable from the calyx and only visible when the coral is 

 cut. It appears then, that all the forms of Parasinilia, Ceralotrochus, and Epiirochus possess a 

 spongy pseudo-columella, and not, as was determined earlier, a true fasciculate columella. 



Zittel: Grundzüge der Paléontologie I. Abll. München u. Berlin. 1915. 

 ^) Vaughan: liocenc and lower oligocène Coral l'"aunas of llie 1'. S. Washington. I). C. 1900. 



