REPORT ON THE REEF-CORALS. 83 
The specimens which I have referred to this species present some very interesting 
variations, but there are no differences constant enough in them to warrant specific 
separation. At least two of them in the absence of the others would seem to be distinct, 
but with the others at hand it is impossible so to designate them, for the series presents 
almost every intermediate condition, while the characters are extremely variable—the 
least variable being that the border of the septa is approximately vertical and the upper 
portion more or less truncate. 
Thus the corallum may be very convex and raised, or slightly convex and broad, with 
a diameter of about 12 em.; the epitheca very rudimentary or more developed; the 
coste very finely spinulose or unequally toothed; the wall very thin, or thick enough to 
show a small furrow above; the calicles separate, or in series straight or sinuous, scarcely 
or nearly separated, deep or comparatively shallow, wide or narrow; the septa thin or 
thickened, with long or short teeth, very close or rather far apart according to the greater 
or less development of the last cycle; and the columella slightly or much developed ; 
while at the same time these differences are most irregularly marked on different 
specimens. 
Three forms may be selected as showing the extremes of variation :— 
a. One with a very regularly raised, convex corallum ; thin walls; rather large 
and deep calicles in sinuous series of from two to six centres; thin, vertical and 
truncate septa; very sharp, long and rough teeth giving a jagged appearance 
to the ealicle ; columella well developed. 
}. Another with a very raised, convex, somewhat oblong corallum ; thick walls ; 
large, deep calicles in nearly straight series with scarcely distinct centres ; 
thick, scarcely vertical and truncate septa; sharp and rough teeth ; columella 
well developed. 
ec. A third with a very broadly convex corallum; thin walls; small, shallow 
calicles, separate or tending to be so; thin, rather narrow septa, somewhat 
vertical and truncate; short, sharp and rather small teeth, and a slightly 
developed columella. 
The Symphyllia anemone, Duchassaing and Michelotti, must, I think, be placed as 
a synonym of this species, and perhaps also the Symphyllia agle. The Isophyllia 
rigida, Verrill, as re-described by Pourtalés under Isophyllia guadulpensis seems also to 
be indistinguishable from the broad variety of the species. The Madrepora lactuca, 
Esper,! seems to be the above species, but I have taken the name of the later authors to 
avoid ambiguity and doubtful identification. 
Locality.—Bermuda. 
1 Pflanz. Forts., i. Tab. xxxiil. 
