138 Reports and Proceedings— 
S. subramosa as a synonym of Astrea ramosa, Defrance—an appa- 
rently recent species of coral which had previously only been informally 
described by Defrance. They also included in the genus S. Forbesz, 
the original specimen of which was from the Miocene of Maryland, 
and at that time in the collection of the Geological Survey in 
London. Later on, in 1852, D’Orbigny claimed that S. Forbes 
was but a synonym of his S. subramosa. There is good reason for 
regarding this as correct, but owing to the fact that D’Orbigny’s 
name subramosa was merely nominal and without description, the 
later name of S. Forbesi, Edwards & Haime, must be allowed to. 
stand for the type of the genus Septastrea. 
In 1861 de Fromentel, and in 1867 Prof. Duncan, included in 
Septastrea several species of Jurassic and Liassic corals, which, 
however, have no generic relationship to the type form of the genus. 
from the Miocene Tertiary. 
In 1887 Prof. Duncan read a paper before the Geological Society, 
in which he adopted Septustrea Forbesi, H. & H., as the type of a 
new genus Glyphastreea, thus leaving in Septastrea those Liassic 
and Jurassic species placed therein by himself and de Fromentel. 
As this proceeding is contrary to recognized rules of nomenclature, 
the genus Glyphastrea will have to be abolished. 
In the type form of Septastrea, now in the British Natural- 
History Museum, the walls of the corallites, though closely apposed, 
are quite distinct ; the theca is formed by the extension of the septal 
laminz; the walls and septa in the lower portion of the corallites. 
are very thin, but the upper portion of the corallites are so infilled 
with compact stereoplasm that the calices are extremely shallow 
when mature. There is no true columella, only a pseudo-columella, 
formed by the union and partial involution of the inner septal 
margins. The increase is inclusively by marginal gemmation; 
fission does not occur. In some cases linear perforations between 
the septa are shown; these appear to be for the insertion of the 
mesenterial muscles. 
Tha septa in Septastrea consist of a central layer, dark in micro- 
scopic sections, the primary layer of v. Koch or centre of calcifica- 
tion of Bourne and Fowler, enclosed on both sides by layers of 
compact subcrystalline stereoplasm. In longitudinal fractures the 
septa frequently split in the centre of the dark or primary layer, 
and thus show that each half of the septum consists of a dark and 
light portion, and the median face of each septal lamina exhibits. 
transverse growth-lines, not unlike those of an epitheca, beneath 
which are delicate longitudinal ridges and grooves. The thecal wall 
has a similar structure to that of the septal lamine, of which it is. 
an extension. 
There is a close correspondence in the septal and thecal structure- 
of Septastr@a to that of the recent and fossil genus Flabellum, and 
in this genus also the septa occasionally split longitudinally and 
show the same growth-lines on their median faces. 
Only two species are included in Septastrea, as now defined, 
viz. S. Forbesi, H. & H., and S. (Columnaria?) sexradiata,. 
Lonsdale, sp. 
