A chart of the Rugose corals. — Sherzer. 
301 
DISTINGUISHING CHARACTERISTICS. 
RAXtJE. 
Four of the septa form a cross in the calyx. 
Absence of vesicles. See also Holocystis. 
No defined columella. 
Silur. 
Silur., 
Devon. 
Strong' walls, presence of columella. The cor- 
allites are more individualized. 
1. No true columella; uncovered central tabu 
late area. 2. Abortive condition of the se] ita. 
1. Rudimentary fovea and tabula-. 
2. Stunted principal septum in fovea. Coarse 
septa. 
Peculiar trumpet-shaped corallum. 
Silur., 
Devon. 
Low. Car 
bon. 
MAXIMUM. lUSTRIIiimoS. 
Up. Silur. 
Europe. 
Silur. 
Silur. 
Low. Car 
bon. 
Carbon. 
Carbon. 
Devon. 
Compound growth, 
of walls. 
Rudimentary condition 
1. Absence of true septa and tabulae. Coarse 
vesicles. 2. Simple in growth, better defined 
wall. 
Slender, cylindrical and fasciculate in growth 
Corallites bifurcated and united by trans 
verse filaments. 
Silur. 
Silur., 
Devon. 
Europe, 
America. 
Europe. 
Europe. 
America. 
Low. De- 
von. 
Silur. 
(Niag.) 
Devon. 
Silur. 
Rows of vesicles at the center elevated, form- 
ing a mound-like elevation in calyx. 
Absence of tabula?. 
Rows of vesicles not elevated at the center. 
More complete septal development. 
2. Rudimentary condition of septa and coarse 
vesicles. 
Well developed, horizontal tabulae. Concen- 
trically wrinkled operculum present. Silu 
rian. 
1. No infundibuliform arrangement of tabulae 
Not bifurcate. 2. Visceralcavityhascoar.se 
vesicular structure. 
1.' More slender prismatic growth, and coarser 
vesicular structure. 2. General shape and 
operculum. 
Devon. 
Silur. 
(Niag.) 
America. 
America. 
Europe, 
America. 
Devon. 
(Corn if.) 
America. 
Silur. 
Silur. 
Silur. 
Carbon. 
Silur. 
Absence of radiciform processes. 
Silur., 
Devon. 
1, 2. Square pyramidal shape, more complete 
septa. 2. Absence of radiciform processes. 
Radiciform processes. 
Silur. 
Silur., 
Devon. 
Silur. 
Carbon. 
Silur. 
Devon. 
Silur. 
Silur. 
America. 
Europe. 
Europe. 
Europe. 
Europe, 
America. 
Europe, 
America. 
Europe, 
America. 
Central depression in calyx. Lamellae of cen- 
tral area do not reach center. .All of same 
approximate thickness. 
General absence of the fasciculate arrange 
merit of the septa. The spheroidal cells of 
the center. 
The radial septa, of the central area are some- 
what better developed. 
The fascicled arrangement of the septa ami 
absence of central spheroidal cells. 
Corallites tall and more cylindrical, 
ary sepia not generally present. 
Second- 
The distinctly compressed median columella! 
rod towards which the tabulae are elevated 
is absent. 
22a 
Low. Car- 
bon. 
Low. Car-'., 
. Europe. 
bon. 
Low. Car 
bon. 
Low. Car- 
bon. 
Low. Car- 
bon. 
Low. Car 
bon. 
Devon. 
Carbon. 
Low. Car 
bon. 
Europe. 
Low. Car- 
bon. 
Low. Car 
bon. 
Carbon. 
Europe. 
Europe. 
Eumpe- 
Low. Car- 
1 
Europe. 
