BROWN, RUGOSE CORALS 
85 
Although reported by Hall from the Onondaga (.Corniferous) at the Falls 
of the Ohio, the individuals of this species studied were from the St. Louis 
Group at Button Mould Knob, Ky. In its younger stages, this species 
passes through a development similar to the Streptelasma line, then through 
the Heterophrentis stage and becomes specialized by changing the fossula of 
the Heterophrentis stage into an inner wall. The inner wall condition is 
much more clearly shown in the sectional Hews of El. varsoviense given later. 
The accompanying figures show the typical stages in the life of this form 
after it has attained the Hapsiphyllum characters.' Figure 12 is of a small 
and rather young individual showing a condition hardly distinguishable 
from an Enterolasma or Stereolasma. Figures 13 and 14 show later stages 
with the Hapsiphyllum characters more pronounced, but in none of these 
are these characters as prominent as in the species to be described later. 
Attention is here called to the similarity between the development of the 
inner wall in this species and the development of the inner wall of Craspedo- 
pliyllum subccespitosum, a compound branching form from the Devonic 
described by G. E. Anderson. 1 
Hapsiphyllum spinulosum Edwards & Haime. 
1851 Zaphrentis spinulosa Edwards & Haime, Pol. Foss, des Terr. Pal., p. 334. 
1890 Zaphrentis spinulosa Worthen, Geol. Sur. Ill. vol. VIII, p. 73, pi. X, figs. 
6, 6a. 
In the latter reference, this species is described thus: 
Coral turbinate, moderately elongated, a little curved and slightly distorted, 
with a few irregular external ridges; epitheca thin and on the lower portions orna¬ 
mented with little sub-spiniform points; cup circular, moderately profound; fossette 
moderately developed, situated near the wall but in a variable position from conform¬ 
ing to the curvature; lamellae about 30, very feebly curved near the septal fossette, 
with an equal number of rudimentary lamellae. 
Figures 15 and 16 are two typical sectional views of this species and 
show a slight advance over the preceding species. The inner wall is a trifle 
more prominently developed, and the tertiary septa are longer, more promi¬ 
nent and wider separated from the primary and secondary septa. 
Hapsiphyllum varsoviense Worthen. 
1890 Zaphrentis varsoviensis Worthen, Geol. Sur. Ill., vol. VIII, p. 78, pi. 10, 
figs. 9, 9a. 
1 “ Studies in the Development of Certain Palaeozoic Corals,” Journal of Geology, vol. 
XV, No. 1, 1907. 
