A chart of the Rugose corals. — Sherzer. 
281 
DISSEPIMENTS. 
TABULA. 
CENTRAL AREA. 
None. 
*None in typical species. 
Strong, continuous, styliform col- 
umella. 
None. 
None. 
Columella wanting or non-deter- 
minable. 
Slightly developed. 
None. 
Thin, funnel-shaped inner wall. 
None. 
None. 
No columella. 
None. 
None. 
Styliform columella. 
None. 
None. 
Open to near base. 
None. 
Horizontal, complete, at 
irregular distances. 
No columella. 
None. 
None. 
No columella. 
None. 
None. 
No central structures. 
None. 
None. 
No columella. Some septa reach 
center. 
None. 
None. 
No columella. 
None. 
None. 
No columella. 
None. 
None. 
Broad and smooth. 
None. 
Described as wanting. 
Inner edges of primaries free and 
denticulate. 
None. 
Well developed, horizon- 
tal, reaching to the 
spiny septa. 
No central structure except the 
tabular. 
No true dissepi- 
ments. 
Very strong, complete. 
Frequently bent down- 
ward near the wall. 
Smooth and flat, septa being absent. 
None. 
Little developed. 
No columella. 
None. 
Complete, horizontal. 
Free from septa, only tabulae pres 
ent. 
Well developed in 
the narrow inter- 
septal cavities. 
No true tabula?. 
Septa may be somewhat twisted. 
Transverse dissepiments. 
None. 
< iomplete, invaginated. 
Very oblique and close- 
ly arranged. 
Only the oblique, smooth tabulae 
None. 
Numerous, strong, hori- 
zontal. Not deflected 
at outer edges. 
Generally smooth. No columella. 
None. 
Variously formed, bul 
extend to outer wall. 
No columella. 
Abundant between 
the superposed 
layers. 
Numerous in the \ isceral 
cavity. Bell-shaped. 
False columella. 
* Some species, as Cyathaxonia dalmani,ha.ye been found to possess tabula and 
Lindstrdmia has been proposed for such forms by Thompson and Nicholson (1876). 
