REPORT ON THE REEF-CORAILS. 85 
specific names would doubtless be applied to them, The very convex specimens of the 
typical form gradually pass to those with a much broader growth, which seem to be very 
close to, if not identical with, the Zsophyllia sinuosa, Verrill. In these the convexity is 
very slightly marked, and the cells become more shallow and open and of smaller size,’ 
though this is very variable (1°5 to 3°5 cm.), while at the same time the septa are 
thinner. The slight furrow on the wall between the septa often becomes somewhat 
prominent, and marks an approach to IJsophyllia marginata (Duchassaing and 
Michelotti). The columella in some is well developed, and in others rudimentary. 
An interesting variety occurs in which many of the larger septa are much thickened, 
a variety that calls to mind the Jsophyllia cylindrica, to which it is closely allied. 
The Symphyllia thomasiana, Duchassaing and Michelotti, does not seem to differ in 
any respect from the present species. 
Professor Moseley remarks that this species seems to thrive best in the shade.’ 
Locality.— Bermuda. 
5. Isophyllia marginata (Duchassaing and Michelotti). 
Symphyllia marginata, Duchassaing and Michelotti, Mém. Cor. des Antilles, p. 72. 
This specimen, which is shortly pedunculate, differs from the description of Duchassaing 
and Michelotti in one chief particular, namely, that the columella is here but slightly 
developed, a character that would place it very close to the Isophyllia helvanthus of those 
authors. It is very close to the [sophyllia dipsacea. 
On one side the epitheca is fairly well developed, on the other scarcely present; the 
walls are always fused together up to the edge of the calicles, but flattened above and 
wide enough to leave a well-marked vacant space or furrow between the septa of adjoming 
calicles ; the septa are rather exsert, thin and finely dentate; the calicles are rather small 
and shallow, with measurements somewhat larger than those given in the description ; 
the number of the septa to the centimetre is very variable in different parts according to 
the presence or absence of the septa of the last cycle. 
To this species I have referred, with some doubt, another specimen which is much more 
convex than the foregoing, with an irregularly developed epitheca, a more abundant colu- 
mella, and thicker and rougher septa. It closely agrees with it, however, in the flattened 
wall of the series which gives the characteristic appearance to the species, and as the above 
differences are all in characters which are very variable in the same species, it seems justifi- 
able to conclude that a larger collection of this species would yield forms with less divergence. 
To this species also, it is likely, should be referred the Jsophyllia multilamella 
described by Pourtalés in the Florida Reef-Corals,? of which the Lithophyllia multila- 
mella, Duchassaing and Michelotti, seems to be only a young specimen. 
1 Notes by a Naturalist on the Challenger, p. 27. 2 Tilustr. Cat. Mus. Comp. Zodl., No. iv. 
