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ANNALS NEW YORK ACADEMY OF SCIENCES 
cardinal quadrants. Tertiary septa are also present, adjacent to all the septa 
except the cardinal and the last two pairs of secondary septa in the counter 
and cardinal quadrants. Even in this form, in which the primitive arrange¬ 
ment of the septa is retained and accentuated, the counter quadrants develop 
slightly in advance of the cardinal quadrants. And furthermore, although 
this is a highly specialized form, it is clearly seen that it is derived from a 
Streptelasma-like ancestor, and the genus Microcylus probably connects this 
with the Streptelasma line. 
IV. Carbonic Corals. 
In the Devonic deposits we find sufficient evidence to prove that the 
rugose corals have passed the acme of their development and are on the 
decline. During the middle and latter part of the period typical progressive 
species become less abundant and their place is taken by highly specialized 
terminal forms, such as the Heliophyllums with the carinate character, the 
Hadrophyllum with the extremely short almost disc-like calyx and peculiar 
grouping of the septa in the four quadrants retained and intensified in the 
adult stage. At the end of the Devonic and beginning of the Carbonic the 
rugose corals have become a very meagerly represented and unimportant 
group of fossils. Only a very few genera and species yet remain, and, occur¬ 
ring as the last and terminal forms of such a long continued series, they 
might be expected to be specialized forms. 
One of the species in the Carbonic limestones and one similar and 
closely related to the series under consideration in the present paper is 
Lophophyllum proliferum. 
Lophophyllum proliferum Edwards & Haime. 
In their volume on British fossil corals, Edwards and Haime describe 
the genus Lophophyllum thus: 
Corallum resembling Zaphrentis, excepting by the great development of three 
primary septa, one of which is placed facing the septal fossula; this fossula extend¬ 
ing much toward the center of the visceral chamber, and ceasing there to be dis¬ 
tinct from the bottom of the calyx. 
There is considerable material of this species in the collections of Colum¬ 
bia University, and sections were made and the individual development 
studied in the same manner as described in the preceding chapters. In 
sectioning the earlier stages, however, the writer did not meet with as good 
