REPOET OX THE HYDROIDA. 
17 
the means of determining with certainty the nature of the soft parts which fill the little 
accessory cups of Diplocyathus; and the most that could be made out from an examination 
of the preserved specimens was the presence within the cups of simple granular contents, 
which might occasionally be seen to extend beyond the margin, thus suggesting the 
commencement of a pseudopoclial protrusion of the sarcode contents. In other respects 
the agreement between Ophioides and Diplocyathus is so decided that the close affinity 
of the two genera can hardly be questioned. 
The hydrophore in Diplocyathus dichotomies, the only known representative of the 
genus, is funnel-shaped, with a well-developed limbus, a form which closely resembles 
that of the hydrophore in Ophioides mirabilis. In Ophioides as figured by Hincks the 
hydrophores terminate the branches, while in Diplocyathus they are disposed alternately 
from distance to distance along their sides. 
Diplocyathus dichotomies , n. sp. (PI. VIII. figs. 1, 2, 3). 
Trophosome. — Hydrocaulus monosiphonic, dichotomously and profusely branched ; 
branches given off in various planes and frequently reuniting with one another so as to 
form a bulky reticulated mass. Hydrophores widely funnel-shaped, rather closely set, 
alternate, supported through the medium of a very short annular segment on a lateral 
process of the stem. Accessory cups cylindrical, sessile, each seated in the axil of the 
lateral process. 
Gonosome not present. 
Locality. — Off Somerset, Cape York, Torres Strait; depth, 8 to 12 fathoms. 
In its general physiognomy Diplocyathus dichotomies is so distinct as to be easily 
recognised at a glance. It is of remarkably rigid habit, and by the profusion of its 
branches, which extend in all directions, and their frequent union with one another, it 
forms a bulky reticulated mass which forcibly recalls the skeletons of some of the horny 
sponges. 
The ramification is regularly dichotomous, and the branches are here and there — 
but not at exactly regular intervals — intersected by transverse joints. The hydrophores 
with their accessory cups are borne along the sides of the branches in two very regular 
alternate series. Their limbus is well developed, but though the cup it forms is deeper 
than in any of the species of Halecium, the hydranth even in its condition of extreme 
retraction is quite incapable of being included within it, as the soft parts still well 
preserved in the specimens plainly show. In no instance were the hydrophores in the 
specimen continued by the superposition of accessory tubes. 
The accessory cups, which are situated on the distal side of each of the lateral processes 
and in the re-entrant angle between this process and the stem, are cylindrical in shape. 
(zool. chall. Exp. — pakt lxx. — 1888.) Aaaa 3 
