12 THE HYDROIDS. 
they are all of small size. The other two are from the Atlantic, Long Island « 
Sound, and are both large species, 75 to 150 mm. in height. It will be 
interesting to see, when their gonosomes are known, if they are generically 
related. The gonothecae have been seen in the G. longicyatha only, where 
one of them bore an imperfect external capsule. They are all shallow-water 
specimens, apparently, although no exact depth is given for C. (?) spinulosa 
at Port Jackson. : 
Campanulina denticulata, sp. nov. 
Plate 8. 
Trophosome: — The hydrocaulus arises from a simple stolon, is un- 
branched, nearly colorless, monosiphonic, and has a few annulations, two 
to four, at its base. Hydrothecae arise alternately on the hydrocaulus, 
pedunculated, two to five annulations at the base of the peduncle; a dia- 
phragm partly separates the proximal part of the cavity, and this varies 
much in size, in some instances being one third the length of the hydro- 
theca, sometimes deeply campulate, sometimes tapering slightly to the distal 
end, always markedly so to the proximal end, the margin cut into large 
castellated teeth, ten to twelve in number, an operculum of converging seg- 
ments equal in number with the teeth, and arising inside the teeth. 
Gonosome : —Gonotheca irregularly cylindrical, very long, tapering 
slightly at the base, full width at the distal end, external opening terminal, 
not full width and at one side, borne on a peduncle of two annulations aris- 
ing from the hydrocaulus. 
Habitat : — From serial No. 4672, Latitude, South, 13° 11.6’, Longitude, 
West, 78° 18.3’. Depth 2845 fms. Tanner net tow at 400 fms. 
A very delicate form 10 to 15 mm. high. 
In general appearance these specimens have the look of a Campanulina 
with pointed hypothecae (see PI. 8, fig. 2), but with a higher power some of 
them are seen to be campanulate. Some of the hydrothecae have the strue- 
ture shown in PI. 8, figs. 6 and 6}. This seems to be due to two succes- 
sive enlargements of the hydrothecae, starting in each instance from within 
the teeth, in which case the original operculum must have been dropped off 
or else have had its segments united to form the addition and to leave the 
succeeding set of teeth at the new rim. The various sets of teeth persisting 
form an unusual ornamentation, tiara-like in its plan. I have found one 
