570 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXIV. 
Distribution.—South coast of Molokai: Station 3838, 92-212 
fathoms; Station 3853, 115-134 fathoms (Cat. No. 22563, U.S.N.M.) ; 
Station 3859, 1388-140 fathoms. 
Section HOLAXONIA. 
Colony with an axis consisting of amorphous horny or calcareous 
material, or both, and not pierced by longitudinal canals, excepting 
a central one. 
Family ISIDA4 Gray (modified by Wright and Studer). 
Axis cylinder composed of alternating horny and calcareous joints, 
the latter not of fused spicules, but amorphous. 
Genus CERATOISIS Pereival Wright. 
Branches, when present, arising from the calcareous joints of the 
axis cylinder. Polyps nonretractile, a circlet of diverging spicules 
around the oral region. Spicules smooth. 
CERATOISIS FLABELLUM, new species. 
Plate XLIII, fig. 1; plate XLVII, fig. 3. 
All of the specimens were secured in a fragmentary condition. 
The largest piece is about 275 mm. long; calcareous nodes 17 to 27 
mm. long, horny nodes 14 mm. long. The branches arise from the 
calcareous joints, on opposite sides of the stem; irregularly disposed 
but all in the same plane. Polyps on front and sides of stem and 
branches, unequally distributed, often denser on one side than on the 
other, standing at various angles with stem; about 4 mm. high, 2 mm. 
broad, cylindrical. The tentacles are folded loosely over the oral disk. 
Spicules very long needles, attaining a length in some instances of 
5 mm.; vertical in walls of calyces, on the distal portion of which 
they project upward as sharp points between the tentacle bases. The 
proximal part of calyx wall is overlaid with similar long needle- 
shaped spicules, often more or less obliquely disposed. Similar spic- 
ules are sparsely disposed in the cortex, where they are longitudinally 
disposed, and sometimes branched at one end, the two or three 
branches being parallel to the axis of the spicule. 
The main stem and larger branches appear to be somewhat flat- 
tened. The polyps are distributed on all sides of smaller terminal 
branches, but are usually thicker on the edges. 
Color.—Ivory white, the nodes purplish brown. 
Type.—Cat. No. 25390, U.S.N.M., Adbatross Station, unknown, 
Hawauan Islands. 
