REPORT ON CORALS—HYDROCORALLIN &. 65 
is, M some respects, somewhat diagrammatic, but is taken from an actual transverse 
section. The section is taken above the level of the gastrozooid, which hence does 
not appear. The sac of the gastrozooid is, however, seen in section, together with 
its radial supports. The dactylozooids seen in section show the three layers of tissue 
of which they are composed, viz., ectoderm, basement membrane and muscular layer, 
and endoderm; and sections of their styles are introduced to show the position 
of these. The two finer reticulations of the ccenosarcal meshwork, inner and outer, 
are also well seen, with the larger canals in the interval between them, which at 
this height in the wall of the system are confined to the interspaces between the 
dactylozooids. 
Gonophores.—Male examples only were obtained of the present species. The 
ampulle are covered by the surface layer of the ectoderm, and the superficial reticula- 
tions of the ccenosarcal meshwork. Within, they contain a sac (Pl. VI. G) in which 
are developed two or three gonophores of an ovoid form, which are attached to offsets 
of the ccenosarcal canals, and which show the usual elements characteristic of the 
various stages in the development of spermatozoa in the family, which elements are 
massed around a spadix, as in Sporadopora. The process of development was not closely 
fellowed in the present species. 
Astylus, Moseley. 
I formed the above genus for a Stylasterid with regular cyclo-systems, dredged 
off the Meangis Islands in 500 fathoms. The coral is, like Cryptohelia, devoid of 
styles in both kinds of zooids, and differs in structure in no important particular from 
that genus, with the exception that it has no solid lid-like covering overhanging the 
mouths of the zooid pores. It possesses, however, a curious tongue-like process deeply 
seated in the calicle, which probably is the homologue of this lid. 
Ceenosteum of Astylus subviridis,: 
The ccenosteum (PI. I. fig. 4) consists of a short stem, which breaks up into a few 
primary branches. These, with their slender secondary branches and_ branchlets, 
which are very few in number, ramify in the same plane, and form a small flabellum. 
The stem and branches are circular in transverse section throughout their length, 
except where distorted by the presence of zooid cyclo-systems upon them. They are 
composed of a hard and compact pearly-white calcareous tissue, the outer surface of 
which is marked by a series of conspicuous fine rounded ridges, which, separated by 
1 The Hydroid here named Astylus subviridis was referred to in my abstract paper on the Structure of the Stylasteridz 
(Proc. Roy. Soc., 1876, p. 95) as “a Stylaster resembling Cryptohelia.” 
(ZOOL, CHALL. EXP.—PART vul.—1880.) G9 
