360 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
Sertularia complexa Clarke. Fig. 57. 
(Bull. Mus. Comp. Zool., vol. V,No. 10, p. 245.) 
Trophosome. — Colony an nnbranched erect stem attaining a height of about three-fourths inch. 
I lydrothecie tubular, abruptly curved outward distally, aperture bilabiate; the two hydrotheca; of a 
pair actuate for more than their proximal half. Stem internodes below hydrothecte slender, showing 
immediately below the hydrothecae short internal, chitinous processes pointing downward from the 
liydrothecal lioors. Hydranths with conical proboscis and about 20 tentacles. 
Gonosome. — Gonangia produced usually in pairs at foot of stem, ovoid in form, beautifully and reg- 
ularly annulated, resembling Chinese lanterns, collar terminal, with circular aperture and operculum. 
Distribution. — Found by Mr. Walmsley near Woods Hole, and afterwards by myself, growing in 
great quantities over seaweed dredged from the bottom near Nobska Point. 
This interesting species was originally found by the Blake off the coast of Yucatan, then reported 
from Australia by Professor Bale, and finally proves to be common near Woods Hole, where it lias 
doubtless often been mistaken for S. pumila. 
DIPHASIA. 
Trophosome. — Colony regularly branching; stems and branches regularly divided into internodes, 
each of which bears a pair of opposite hydrotheece. Hvdrothecal margins even or sinuous, with an 
internal operculum consisting of a single piece. 
Gonosome. — Gonangia cleft above into leaf-like segments, and containing a spherical, internal 
marsupial chamber. 
Key to species of Diphasic/, found in the Woods Hole region. 
Width of a pair of hydro theca; at base nearly equal to their height D. fallax. 
Width of a pair of hydrothecae at base not much more than half their height D. rosacea. 
