A chart of the Rugose corals. — Sherzer. 
293 
DISSEPIMENTS. 
TV 15UE.E. 
True vesicular outer Well developed, extending 
zone of variable over large central area but 
width. not to wall. 
Tabula? smooth, Hat and free 
from septa. 
Present throughout the Loose, vesicular and rudi- 
corallum. mentary. 
An elongated, slightly raised, 
central boss. 
CENTRAL AREA. 
Dense vesicular zone in 
external portion. 
Limited to central area. 
Lamellar columella. 
Minute vesicular tissue 
arranged in inclined 
rows. 
Present as central, very deli- 
cate, elevated, inosculat 
ing plates. 
Continuous, columellas lam- 
ina. 
Developed to a greater 
or less extent in out- 
er area. 
Confined to central tube-like 
channel. Horizontal or 
slightly inclined. 
Generally well devel- 
oped. 
Present in outer area 
Delicate and irregu- 
lar at center. 
Form a dense zone in 
outer area. 
Confined to center, inter 
r up ted, close-set, concave. 
Scanty in central area, 
abundant in outer. 
Central, delicate, anastomos 
ing; elevated centrally but 
markedly concave up wards. 
Con lined to a narrow 
peripheral zone. At 
times a single row. 
Much developed and 
coarse outside ::f in- 
ner wall ; finer within 
More or less developed 
More or less developed. 
Sometimes nearly 
absent. 
Simple, horizontal or 
slightly convex. 
Numerous, close-set; 
forming a dense out- 
er zone. 
Small and delicate in 
(niter area. Do not in- 
terfere with septa. 
Large, forming an out 
er vesicular zone. 
Coarse a n d formed 
mostly by continuous, 
plicated cups. 
Distinct secondary wall. En- 
tire or horse-shoe shaped. 
Incomplete, confined to a 
central area of various ex- 
tent. 
Septa may become twisted. 
No columella. 
Irregular, incomplete, vesi- 
cular and anastoinosin 
Elevated at center. 
Distinct inner wall enclosing 
a loose columella. 
Raised, over which sinuous 
ridges extend to center. 
Low central eminence. 
Formed by independent, 
straight lamella- and tabulae. 
Elevated toward the center. 
Elevated as in Clisiophyllum. 
Well developed in broad cen 
tral area. Deflected at 
outer edges. 
Tabulse smooth, generally free 
from septa. 
Small. 
Septa may or may not reach 
center. No columella. 
Present. 
Inner e<\^v of large principal 
septum simulates a colu- 
mella. 
Incomplete; confined to a 
more or less extensive cen 
tral area. 
Septa may unite with each 
other. No columella. 
Thick, close-set, not com 
plete. 
Small styliform columella. 
Delicate, close-set, inosculat 
ing, almost vesicular. Ele- 
vated at columella. 
Various in extent, frequently bi- 
furcating and Irregular. Some- 
times centrally elevated. 
Well developed, close-set, of 
ten anastomosing. Ele 
rated at columella. 
Well developed through the 
central area, horizontal 
and smooth. 
Abundant in outer area, 
more; or less devel- 
oped at center. 
Present in peripheral 
area. 
Loculi filled with "like 
formed" stereoplas 
ma. 
( Inter zone of dense lis 
sue in which sepia 
are thin. 
Fill up the larger por 
tion of the visceral 
cavity. 
22 
Well characterized through 
the center. 
Wanting or rudimentary, 
Laterally compressed, some- 
times discontinuous, colu- 
mella. 
Laterally compressed, rod-like, 
continuous columella. 
Large continuous columella 
formed of twisted plates. 
Flat and generally free from 
septa. No columella. 
Primary septa are thin and 
reach center. 
Weak, false columella. 
Regular, equidistant. 
[r regular, vesicular ,verydellcate 
siijinh concave upwards iu- 
tween the lamellar plates. 
Some small, horizontal tabu 
he at the center. 
Formed by tabula- and a lew 
vertical, spirally twisted 
plates. 
No columella nor inner wall. 
