950 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Thuiaria fenestrata Bale. 
Distribution. — Station 3955, north of Laysan Island, 20 fathoms; station 4068, northeast of Maui 
Island, 14 fathoms. 
Thuiaria fenestrata Bale, Catalogue of the Australian Hydroid Zoophytes, 116, 1884. i 1 
Genus DIPHASIA. 
Trophosome. — Hyd rothecse biserial, opposite or alternate, aperture broad, operculum evident and 
consisting of a single adcauline flap. 
Gonosome. — Gonangia usually with an internal marsupium and often marked with spines or lobes 
on its distal portion. 
Diphasia palmata Nutting, new species. 
(PI. iv, fig. 6; pi. xi, figs. 8-10.) 
Trophosome. — Colony attaining a height of about 1 inch. Stem not fascicled, smooth without 
nodes or hydrothecse for some distance, breaking suddenly into a number of widely divergent 
branches, which again divide into branchlets, all being in the same plane. Branches with very faint 
nodes just above the hydrothecas. Hydrothecse much as in D. rosacea, opposite, tubular, their 
proximal three-fourths vertical and parallel, their distal portions being bent abruptly outward. 
Margin even, Operculum of a single strong adcauline flap. 
Gonosome. — Gonangia (female) borne in rows on front of branches, each composed of four very 
unequal gonangial leaves, one of which is much longer and broader than the others, imparting a very 
unsymmetrical appearance to the whole gonangium. Leaves notched near their ends in some cases. 
There is an evident internal marsupium of the type characteristic of the genus. 
Locality. — Station 3854, south coast of the island of Molokai, 134 fathoms. 
This is a well-marked species of a genus that has no other typical representative this far to the 
south, so far as I know. The manner of branching is very unusual in Diphasia. 
Genus SYNTHECIUM. 
Trophosome. — Branches opposite, with regular nodes. Hydrothecal margins smooth, round, -- 
often rimmed or reduplicated. Operculum apparently wanting. 
Gonosome. — Gonangia springing from the interior of hydrothecae, where they replace hydranths. $ 
Synthecium tubithecum (Allman). 
Distribution. — Station 3819, south coast of the island of Molokai, 70 fathoms; station 4053, north- 
east coast of the island of Hawaii, 29 fathoms. 
This species has not before been reported from the Pacific. 
Sertularia tubitheca Allman, Mem. Mus. Comp. Zoo]., Yol. V, 1877, No. 2, 24. 
Synthecium orthogonia (Busk). 
Locality. — Station 4068, northeast coast of Maui Island, 14 fathoms. 
But a single fragmentary specimen was found. It agrees well with the figure and description given 
by Bale (proceedings of the Linnsean Society of New South Wales, 1888, page 767). 
Sertularia orthogonia Busk, Voyage of Rattlesnake (Narrative, Appendix IV, 1852). 
Family PLUMULARIMi. 
Trophosome. — Hydrothecse adnate to hydrocaulus and on one side only of hydrocladia. Hydranths 
with a conical proboscis and a single whorl of filiform tentacles. 
Gonosome. — Gonangia often inclosed in corbulse, or protected by special nematophorous branches. 1 
Medusae never produced. 
Genus PLUMULARIA. 
Trophosome. — Coenosarc of stem not canaliculated, hydrocladia unbranched, hydrothecse with 
smooth margins, nematophores always movable, not adnate. 
Gonosome. — Gonangia simple sac-shaped or bottle-shaped. 
