10 
THE VOYAGE OF H.M.S. CHALLENGER. 
family the remarkable genus Ophiodes of Hincks will also find a place, while I am 
strongly of opinion — though I have had no opportunity of examining a specimen — that 
we ought to bring into the same association the singular genus, Hydranthea , Hincks, 
which Mr. Hincks places among the Gymnoblastic Hy droids. 
Halecium robustum, n. sp. (PL IV. figs. 1-3). 
Trophosome. — Colony attaining a height of upwards of eight inches ; stem profusely 
and irregularly branched, with the branches extending for the most part, but not 
exclusively, in a single plane ; main stem and principal branches very thick, fascicled ; 
ultimate branches monosiphonic, disposed in alternate pinnae, each springing from the 
side of the basal segment of a hydrophore ; pinnae divided into short internodes by 
obliquely transverse joints, each internode supporting on alternate sides a hydrophore with 
a very narrow non-everted limbus ; basal segment of hydrophore adnate by its side to 
the hydrocaulus. Hydranths very large, with about eighteen tentacles. 
Gonosome not present. 
Locality. — Station 149 j, off Cumberland Bay, Kerguelen Island; depth, 105 fathoms. 
This is a large and very robust form, the stem towards the root measuring a quarter 
of an inch in diameter, and the principal branches two-tenths of an inch. The primary 
segment of the hydrophore is adnate to the internode, and is frequently prolonged by 
two or three supplementary tubuli. The limbus of the hydrophore is exceedingly 
narrow, and is marked by a girdle of minute brilliant points. 
The presence of a zone of refringent puncta on the almost evanescent limbus of the 
hydrophore of Halecium robustum points to the all but universal presence- of this 
apparently insignificant character throughout Halecium and its immediate allies. In 
only one instance among the various species of Halecium which I have examined have I 
failed to detect these puncta, though the specimens had been obtained from very various 
and widely distant localities. 
The soft parts are in this fine species, as in almost all the Haleciidse contained in the 
collection, sufficiently well preserved to admit of the form of the hydranth being observed 
in most of its important features. 
Halecium telescopicum, n. sp. (PI. V. figs. 1, la). 
Trophosome. — Hydrocaulus irregularly branched, with the branches given off nearly 
in one plane. Hydrophores with the limbus narrow and slightly everted, and with the 
first of the accessory segments provided with two oblique annuli at its base. 
Gonosome not present. 
Locality. — Station 163b, off Port Jackson; depth, 30 to 35 fathoms. 
The branches of this species are very slender and flaccid, and the internodes of 
