A chart of the Rugose corals. — Sherzer. 
283 
DISTINGUISHING CHARACTERISTICS. 
RASttE. 
MAXIMUM. 
DISTRIBUTION. 
1. Absence of tabulae and dissepimental struc- 
tures. Columella forms a single, continuous 
rod. 2. Character of base and columella. 
Silur., 
Carbon. 
Carbon. 
Europe, 
America. 
Epitheca wanting at the base. Septa seem- 
ingly in multiples of six. 
Silur. 
Silur. (Niag.) 
America. 
Total absence of tabulae. Wall is thin and 
funnel-shaped. Secondary septa very short. 
Carbon. 
Carbon. 
Europe. 
More completely developed septa and hence 
more shallow calyx. 
Silur. 
Silur. 
Europe. 
Recent. 
Recent. 
Character of base and columella. Recent. 
Recent. 
Recent. 
America. 
1. Considered synonymous by some. 
2. Calyx very deep ; septa complete only near 
ha.se. 
Silur., 
Devon., 
Carbon. 
Silur. 
Europe, 
America. 
Silur., 
Carbon. 
Carbon.(Per- 
mian.) 
Europe. 
Difficult to separate and considered synony- 
mous by some. 
Silur., 
Carbon. 
Silur. 
Europe. 
Simple, bowl-shaped or short conical. Absence 
of tabula?. 
Silur. 
Silur. 
Europe. 
But one fovea, indistinct, which with the three 
principal septa form a cross. 
Devon. 
Devon. 
Europe, 
America. 
1. Absence of epitheca. Much longer septa. 
2. Distinct fovea, to which septa are pinnate. 
No epitheca. 
Devon. 
Devon . 
Europe. 
Has four foveas which form an indistinctly 
defined cross. 
Devon. 
Devon. 
Em-ope, 
America . 
Well developed epitheca. Septa are much 
shorter, leaving a bi-oad, smooth, central 
area. 
Devon. 
Devon. 
America. 
Presence of epitheca. Fovea is indistinct, 
septa radiate and strongly granulated on 
- faces. 
Silur. 
Silur. 
Europe, 
America. 
Simple or aggregated, sub-conical to cylindri- 
cal in form. Tabulae quite well developed. 
Silur. 
Silur. 
Europe. 
1. Shorter septa and less pronounced fovea. 
2. Fovea present. Regarded as including this 
genus. 
Silur., 
Devon., 
( tarbon. 
Low.Carbon. 
Europe, 
America. 
Lengthened fovea containing dwarfed sep- 
tum. Weaker development of tabulae. 
Silur., 
Devon. 
Silur. 
Europe. 
America. 
Has no fovea, but this is quite generally con- 
sidered as non-distinctive. 
Silur. 
Silur. 
Europe, 
America, 
Septa an- nut vertical plates but formed of su 
perposed layers. Tabulae absent. [nteYsepta 
cavities very narrow near wall. No carinas. 
Silur.. 
Devon. 
Devon. 
Europe, 
America. 
Septa consist of mere ridges over the tabulae 
Tabula? are quite oblique. 
Devon. 
Devon. (Cor- 
nif.) 
America. 
Stronger and more numerous tabulae. Septi 
ordinarily are not SO complete ; al times rmli 
mentary. 
- Silur. 
Silur. 
Silur. 
Europe, 
America. 
1. Not always simple. Longer septa. 
2. Shorter septa. Not always simple. 
Silur. 
Europe. 
False columella. Silur. 
Silur. 
Europe. 
