DESMOSCYPHUS. 25 
the specimens are immature, and would have acquired a greater develop- 
ment in their adult state, it is a much smaller form than S. pumila. Fur- 
ther, in S. pumila the opposed sides of the hydrothece composing each 
pair converge from above downwards, while in S. ezigua they are parallel. 
Sertularia distans. 
alee ee hes. 9 Vt). 
Trophosome. — Hydrocaulus attaining a height of about an inch, simple 
or with an occasional branch; internodes rather long and prolonged by an 
attenuated extension below each pair of hydrothecee. Hydrothece tubular, 
with the distal half free and divergent, and the opposed sides of the proxi- 
mal halves parallel. 
Gonosome not known. 
Dredged off Tennessee Reef from a depth of 21 fathoms. 
This species bears considerable resemblance to S. pumila, from which, 
however, it differs in the much greater length of its mternodes and con- 
sequent distance of its pairs of hydrothece. The orifice of the hydrotheca 
is cut off obliquely above and below, so as to present two broad lateral 
teeth, and the intervals between these are closed by two thin membra- 
nous valves. Each of these valves is composed of delicate superimposed 
laminz, which may be usually seen partially separated from one another, as 
thin exfoliating films. 
The species resembles also S. gracilis Hassall in the length of its inter- 
nodes, but it is a larger form. 
In the absence of gonosome it is impossible to approximate it closer 
to any European form. 
DESMOSCYPHUS Atiman nov. gen. 
Generic CHaracter. Trophosome. —Hydrocaulus jointed, each internode 
corresponding to one or more pairs of hydrothece. Hydrothecx adnate to 
one another in pairs, each pair adnate to the side of the hydrocaulus. 
Gonosome. — Gonangia simple, borne along the front of the hydrocaulus. 
The genus Desmoscyphus was originally constituted for a hydroid from 
the New Zealand shores.* It resembles most of the species of Thuiaria in 
the extent to which the hydrothecx are adnate to the hydrocaulus, but it 
* Allman on New Genera and Species of Hydroida, Journ. Linn. Soc. Zodlogy, Vol. XII. 
4 
