REPORT ON THE REEF-CORALS. 49 
mm. wide, not deep, often shallow, close in the same spiral line, and generally very 
prominent, especially at the basal parts of the branches, where they are about 4 to 8 mm. 
above the general surface. They are circular, with the sides nearly at right angles to the 
general surface, but towards the proximal parts the bases of the calicles are swollen in 
such a manner as to form a concavity from the edge of the calicle to the general surface 
of the corallum. The calicular fossa is moderately deep in the very prominent calicles, 
but shallow in the others. The coste are very distinct, long and curved; the septa are 
exsert, rather thick and subequal, the primaries being a little thicker and longer than the 
secondaries or tertiaries ; the pali are well-developed but rather thin, and arranged as in 
Oculina speciosa, often nearly filling up the calicular fossa, the secondaries being larger than 
the primaries and forming an outer circle ; columella generally well developed. 
As pointed out by Verrill and Pourtalés, this species is distinct from Oculina diffusa, 
of which Milne-Edwards and Haime had supposed it a synonym. It is also quite different 
from Oculina petiveri, which Pourtalés had supposed to be its synonym. From the 
following additional characters of the Oculina petiveri, it will be seen how distinct it is 
from the present species: the costee are scarcely marked and short; the bases of the 
calicles are much swollen, but broad rather than high, so that a distinct convexity is formed 
from the edge of the calicle to the general surface ; the septa are very thin, not exsert, 
and project but very slightly at their upper portion towards the centre of the calicle ; 
the pali are extremely thin and are simply the inner prolongations of the septa, being not 
at all distinct from these nor from the columella. 
The Oculina varicosa is very close to the Oculina virginea, Lamarck, from the 
Indian Ocean (4), the specimen of which from the collection of Lamarck is in the Paris 
Museum ; and, indeed, it may be oubted whether they are specifically distinct. The only 
character that apparently separates them is the degree of prominence of the calicles, 
especially of those on the basal parts of the branches. In the Oculina varicosa the 
prominence increases from the distal to the proximal part of the axis, becoming very 
great at the base, while in Oculina virginea they are usually less prominent at the basal 
parts than at the middle of the branches, being about 2 mm. above the general surface. 
Very good figures of the species are given in the Report on the Florida Reefs, in 
which pl. ii. shows the characteristic form, while pl. i. represents the variety with scarcely 
prominent calicles: magnified views of the calicles showing their essential structure are 
given in pl. ii. fig. 4 and pl. ili. figs. 8, 9. 
Localities.—Bermuda; St. Thomas. 
4. Oculina coronalis, n. sp. (Pl. L. figs. 6—6e). 
Corallum arborescent, large, very much branched, 10 to 14 mm. thick below, becom- 
ing very attenuated above; branches and_ branchlets about 2 to 10 cm. long, often 
(ZOOL. CHALL. EXP.—PART XLVI.— 1886.) Zz. 7 
