A chart of the Rugose corals. — Sherzer. 
289> 
DISTINGUISHING CHARACTERISTICS. 
Regarded as synonymous by Zittel and Lind 
strom, but retained by Thompson. 
Tabula? strongly convex upward. Large col- 
umella projecting in the calyx; character 
of which differs from that of Streptelasma 
RAJ[«E. 
Silur. 
Pseudo-columella generally present, 
ently but a single tabula. 
Appar 
Tabulae complete. Non-continuous columella 
in contact with two of the principal septa 
Presence of the three fovea? and the crescent 
iform tabula?. 
The quadrifascicular arrangement of 
septa. 
the 
Differs simply in being compound. 
1, 2. Principal septum is stunted and in fovea. 
Bounding septa and three other principal 
septa strong. 
Much weaker development of tabula?. 
False columella, single fovea, and general ab- 
sence of radiciform processes. 
Zittel and Lindstrom include Densiphyllum 
under this genus. 
Silur. 
Devon. 
Devon., 
Carbon. 
Carbon. 
Devon. 
Silur. 
Carbon. 
Carbon. 
Silur. 
Silur., 
Devon. 
Silur. 
Corallum is branched. 
1, 2. Columella is composed of fine, anasto 
mosing, branching tubes instead of being 
spongy. 
1. Growth is simple. 
2. See Grewingkia. 
1. More completely developed septa and fovea, 
2. Simple. See also Heterophrentis, Polydi- 
lasma, etc. 
Instead of carina? the side faces of the septa 
have thorny outgrowths. 
1. Septa complete in outer area. Epitheca 
well developed. 2. Inner wall present or in- 
dicated. Septa shorter. 
Columella is in the form of a vertical plate in- 
stead of a compressed median rod. 
1. The central area is not completely divided 
by a strong median lamella. 2. Eminence 
helmet-shaped, character of tabulate area. 
Silur. 
Silur. 
Silur., 
Devon. 
Silur., 
Devon., 
Carbon. 
Silur., 
Devon. 
Silur., 
Devon. 
Devon. 
MAXIMUM. 
Silur. 
Silur. 
Devon. 
(Cornif.) 
Carbon. 
Carbon. 
Devon. 
DINTRIBITIO.V. 
Europe. 
Europe. 
America. 
Europe, 
America. 
Europe. 
Europe. 
Carbon. Europe. 
Silur. 
(Niag.) 
Silur. 
Fovea is not replaced by a principal septum 
No columellar structure within inner wall ; 
composed of radial lamella? united by vesic- 
ular structure. 
Simple. Septa better developed in outer area 
I and reaching the outer wall. 
Stronger projecting cell cups; more rudimen- 
tary septal and vesicular development. 
Low. Car 
bon. 
Silur. 
(Niag.) 
Silur. 
Silur. 
Devon. 
America. 
Europe, 
America. 
Europe. 
America. 
Europe. 
Europe, 
America. 
Silur. 
Devon. 
Devon. 
Silur., 
Devon. 
Devon., 
Carbon. 
Carbon. 
Silur., 
Devon. 
Low. Car 
bon. 
Devon. 
Carbon. 
Carbon. 
Europe, 
America. 
Europe. 
Europe, 
America. 
Europe, 
America. 
Europe. 
Europe, 
America. 
Europe, 
America. 
Devon. 
Europe, 
America. 
America. 
genus to have been founded upon a Cyathophyllum. Prof. James Hall has re- 
ferred eleven species to the genus. 
