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 genencally 

 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. (?) sjnnulosa 

 at Port Jackson. 



Campanulina denticulata, sp. nov. 

 Plate 8. 



Trophosome : — The hydrocaulus arises from a simple stolon, is un- 

 branched, nearly colorless, nionosiphonic, 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 ecpial 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. ;?), but with a higher power some of 

 them are seen to be campanulate. Some of the hydrothecae have the struc- 

 ture shown in PI. 8, figs. 6 and 6b. 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 



