944 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
strips and meet in a ridge-like line above. The reduplication of the margin often complicates the 
structure of the operculum, which is then itself duplicated. Bottom of the hydrotheca with a distinct 
septum. Hydranths long and slender, with about 16 tentacles and a conical proboscis. 
Gonosome. — Gonangia rather shorter than the hvdrothecae and nearly sessile, slender, narrowing 
very gradually below and ending in an operculate margin much like that of the hydrothecae. Blast- 
ostyle bearing several male gonophores. 
Distribution. — Station 4102, between the islands of Maui and Molokai, 122 fathoms. 
Stegopoma gracilis Nutting, new species! 
(PI. in, fig. 2; pi. vm, figs. 8, 9.) 
Trophosome. — Colony parasitic. Pedicels springing from a nonfascicled creeping stolon. Hydro- i 
thecae much smaller than the preceding, but otherwise almost a miniature of S. gilberti. 
Gonosome. — Gonangia springing from rootstock, stout, decidedly longer than the hydrothecae, the 
margin and operculum as in the hydrothecae. 
Distribution. — Station 4000, south of Kauai Island, 213 fathoms, station 4098, north coast of Maui 
Island, 95 fathoms, station 4101, between Maui and Molokai islands, 143 fathoms. 
The entirely different habit of this species and its constant difference in size seem to sufficiently 1 
distinguish it from the preceding. 
! 
Stegopoma plumicola Nutting, new species. 
(PL in, fig. 3; pi. ix, figs. 2, 3.) 
Trophosome. — Colony parasitic on Lytocarpus phceniceus and consisting of sessile hydrothecae borne 
on a creeping stolon. Hydrothecae smaller and more robust than in S. gilberti, four or five times as 
long as wide, the ends beveled on opposite sides so as to form 2 long, broad, pointed teeth, between 
which the operculum, consisting of many narrow strips, is placed. - 
Gonosome. — Gonangia sessile on the rootstock, decidedly longer than the hydrothecae margin, 
circular, but with a two-fiapped operculum in the shape of an A tent. 
Locality. — Station 3939, northwest of the island of Laysan 163 fathoms. 
Genus OPERCULARELLA. 
Trophosome. — Stem not fascicled. Hydrothecae ovate in outline, the margin not distinct, its distal 
portion being produced into a number of narrow pointed strips which converge to form a conical 
operculum. 
Gonosome. — The mature gonangia bear acrocysts. 
? Opercularella longicauda Nutting, new species. 
(PI. in, fig. 5; pi. ix, figs. 4-7.) 
Trophosome. — Colony parasitic on another hy droid, growing in tufts of pedicels from a creeping I 
rootstock. Pedicels very long and slender, not annulated even at ends, sometimes five times as long 
as the hydrothecae. Hydrothecae small terete, very thin and collapsible, distal ends broken up into a 
many-parted operculum which sometimes introverts as in Calycella syringa. 
Gonosome. — G-onangia borne on the rootstock, very large in comparison with the size of the hydro- f 
thecae, deep urn-shaped with flaring campanulate margin and a flat operculum composed of several well- ;j 
marked segments. The single gonangium found almost certainly belongs to this species, being found 
buried among the pedicels of the hydrothecae. In dissecting the rubbish in which it was imbedded, 
the short pedicel broke before the connection with the rootstock from which the hydrothecae sprung ji 
was proved. 
Locality. — Station 3859, between Molokai and Maui islands, 138 fathoms. 
Genus CALYCELLA. 
Trophosome. — Stem a creeping parasitic rootstock. Hydrothecae with a distinct margin, above which j 
is a distinct, many-parted operculum which is often introverted. 
Gonosome. —Gonangia borne on the rootstock, oval, and bearing globular acrocysts when mature. 
