REPORT ON CORALS—DEEP-SEA MADREPORARIA. 183 
Between these costee near the margin of the calicle are others, short and rudimentary, 
corresponding to the septa of inferior order. The calicle is elongate-oval in form, 
with a more or less sinuous margin caused by twisting or irregular indentation of the 
calicular wall. 
The septa are very numerous, and of three sizes; there are in two specimens from 
twenty-four to twenty-six complete septa on each side. Between each pair of these 
major septa are three septa of inferior order which are incomplete. The major septa are 
shghtly exsert. All the septa are finely denticulate on their free margins, and many of 
them show also dentation on their free margins at some depth in the calicle. The 
columella is lamellar in form, partly spongy in structure, and beset with fine pointed 
granules ; it leads in a direct line between the median major septum at either end of the 
calicle. The fossa is widely open in the upper part of the calicle, but contracts and 
becomes narrow and vertical before the columella is reached. 
This species seems closely allied to Professor Martin Duncan’s Placotrochus costatis ;* 
but from the general appearance of the coral, its roughness, the dentation of its coste, 
and denticulation of the septa, there can be little doubt that it is allied to Antillia and 
the Astreeide. At all events it appears to have no affinities with Placotrochus levis, the 
type of MM. Milne-Edwards and Haimes’ genus, which is hardly separable from Flabellum. 
Extreme height of the largest specimen, 25 mm. Extreme length of the calicle, 
44mm. Length of short axis of the calicle, 17 mm. 
Locality unknown, the label having been unfortunately mislaid, 
Tridacophyllia, Blainville. 
Tridacophyllia cervicornis, n. sp. (Pl. X. figs. 2, 2a, 2b, 2c, Ba). 
This coral resembles Tridacophyllia aleicornis of Mr W. 8. Kent,’ but differs in the 
form of the branches and mode of branching. The corallum is of a yellowish colour. It is 
cyathiform below and attached by a stout cylindrical pedicle, but above the margin of the 
cup grows out into a number of irregularly ramifying branches. These branches, which 
are narrow, flattened lamine, are often recurved at their edges; on their inner faces pro- 
longations of the septa are continued to their very tips ; their outer faces are smooth and 
directly continuous with the outer surface of the pedicle and cup, and like it devoid of 
costee and covered with fine granules disposed in obscure more or less longitudinal 
lines. The calicle has a deep fossa, wide above, but narrow and elongate below. No 
columella is visible in its depth, but the principal septa appear to meet one another at its 
bottom. The septa are numerous, closely set, and of three or four orders; they are 
2 Duncan and Wall, Geology of Jamaica, Proc. Geol. Soc., Nov. 1864, p. 9, pl. fig. 4, a, 0. 
? Proc. Zool. Soc., 1871, p. 283. 
