REPORT ON CORALS—HYDROCORALLIN &. 95 
coenosteum in the male (?) Gastrozooids cylindrical, with four club-shaped tentacles and 
four basal canals. Dactylozooids entirely retracted. | Gonophores in the female solitary 
in the gonangia. The free margin of the cup-shaped spadix becomes converted into a 
ramified fringe, embracing the embryo as development proceeds. Planula as in 
Pliobothrus. Structure of male stocks unknown. 
4. Distichopora, Lamarck. 
Coenosteum branching flabelliform, with branches usually flattened in the plane of 
the flabellum ; composed of very compact ccenenchym. Pores in most species confined 
to narrow lines or rows running along the exact centres or edges of the sides of the 
branches, usually absent on their faces, except as occasional abnormalities or rudimentary 
branchlets budding in a direction out of the plane of the flabellum. The lines of 
pores composed of three rows, a central row of larger gastropores with circular or 
oval mouths; and a row on each side of this of smaller dactylopores, sometimes 
very minute, sometimes prominent and tubular, often slit-like in aperture, the length of 
the slit being directed at right angles to the line of the row. Pores very deep, prolonged 
in curved lines side by side in the plane of the flabellum, inwards and downwards towards 
the bases of the branches; forming thus throughout the flabelluam a thin continuous 
out fanwise, separating from one another the compact masses of coenenchym forming 
the opposite faces of the branches. The branches may, therefore, be readily split into 
two halves along this tubular tract. Older gastropores with immensely long filiform 
styles; those in the younger gastropores much shorter. Dactylopores devoid of styles. 
Ampullz sometimes on one, sometimes on both faces of the flabellum, prominent in the 
females and often forming confluent masses ; sunk beneath the surface of the ccenosteum 
in the males and invisible exteriorly. Soft structures closely like those of Hrrina. 
Dactylozooids with very long retractor muscular slips; gastropores with four clavate 
tentacles. Gonangia as in Hrrina in the females; in the males, containing four or 
five ovoid masses of spermatozoa." 
5. Labiopora, Moseley” (PI. IIL. fig. 5). 
(Type specimen in British Museum ; mistaken by Gray for a Bryozoon, and described 
by him as Porella antarctica), (Proc. Zool. Soc., 1872, p. 746, pl. Lxiv. fig. 4).—Coenosteum 
minutely reticulate in texture, composed of a few rounded branches with tapering 
extremities. The entire surface covered with nariform projections, with elongate cavities, 
which are arranged in rows along the lengths of the branches, often disposed with great 
regularity for long stretches. The projections of very uniform shape, and rising from the 
1 Some specimens dredged off the Tristan da Cunha group are probably males, having the ampulle small, and 
buried in the substance of the ccenosteum. 
? Prelim. Report, Phil. Trans. Roy. Soc., 1878, part 2, p. 476. 
