BROWN, RUGOSE CORALS 
75 
The cardinal septum, although very short, is still present. The alar septa 
and the secondary septa in the cardinal quadrants are less strongly devel¬ 
oped than the septa in the counter quadrants. Tertiary septa are developed 
adjacent to all septa except the cardinal and the last two pairs of secondary 
septa in the counter quadrants. These latter are not fully developed as yet, 
and a later stage would show tertiary septa adjacent to them also. It will 
be noted that the two tertiary septa adjacent to the counter septum are no 
longer attached to this septum at their inner borders but project freely into 
the interseptal space. 
Attention is further called to the fact that in the adult of this species there 
are eight secondary septa in each counter quadrant while there are only four 
in each cardinal quadrant, a condition similar to that found in the Stereo- 
lasma forms. The earlier stages of this form might easily be taken for those 
of a member of the Streptelasma group, and the whole individual develop¬ 
ment may be taken as that of a Streptelasma form with one new stage added 
as a final adult condition, namely: the fossula stage. Compare the open 
spaces or incipient fossula of Stereolasma rectum, which is a parallel develop¬ 
ment though less accentuated. 
Heterophrentis multilamellosa Nicholson. 
1875 Zaphrentis multilamellosa Nicholson, Paleontology of Ohio, vol. II, p. 236. 
Heterophrentis wortheni Nicholson. 
1875 Zaphrentis wortheni Nicholson. Paleontology of Ohio, vol. II, p. 235. 
Heterophrentis edwardsi Nicholson. 
1875 Zaphrentis edwardsi Nicholson, Paleontology of Ohio, vol. II, p. 235. 
Heliophyllum halli Edwards & Haime. 
1850 Heliophyllum halli Edwards & Haime, British Fossil Corals, p. 235, pi. LI, 
fig. 3. 
Heliophyllum halli is a coral found in abundance in the middle Devonic 
shales of Eastern North America. Edwards and Haime describe it thus: 
Corallum simple, turbinate, or cylindrico-conical, usually elongated, and slightly 
curved at its base, provided with an epitheca and presenting slight circular swel¬ 
lings. Calice circular, rather deep, with a small septal fossula. Septa (80 or even 
more) very thin, closely set, rather broad at their upper end, where they are arched 
and denticulate, alternately larger and smaller, slightly twisted near the center 
