366 



BULLETIN OF THE BUREAU OF FISHERIES. 



number are located midway between the points where each of the adjoining chymiferous tubes connect 

 with the circtimferential tube; the tentacles and the entire surface of the bell are well supplied with 

 nematocysts. ' ' 



Still later, in 1897, Hartlaub concluded that he was the first to discover the gonosome of the species. 

 It is not necessarj' to go over his description as his species would naturally agree with Hincks's. This 

 point might be mentioned, however: The length of the gonothecal pedicel described and drawn by 

 Hartlaub more nearly agrees with Clarke's than with Hincks's. 



The specimens obtained in this material resemble those of Clarke's in that the annulations of the 



stem are single and some distance apart, giving the 

 stem a segmented appearance, like the stem of a 

 coralline . 



No gonosome was present. In the figure, the gono- 

 phores, as drawn by Hincks, Clarke, and Hartlaub, 

 are shown for comparison. 



Family HALECIDiE. 



Trophosome. — Hydrothecae reduced to saucer- 

 shaped hydrophores, which usually pass without con- 

 striction, into tlie broad tubular pedicels; they are too 

 small to lodge the contracted hj'dranth; margin entire, 

 often flaring; reduplication common; hydrophore with 

 a circle of bright dots just below the rim; hydranth 

 with conical proboscis. 



Gonosome. — Gonophores produce sporosacs, usually 

 different in the two sexes. 



Genus HAIECIUM. 



Characters as in the family. 

 Key to Species of Halecium Found in the Beaufort Region. 



Fig. 27. — Halecium beani (Johnston). A, portion of col- 

 ony; B, female gonosome (after Hincks); C, male gono- 

 some (after Hincks). 



A. Female gonangia surmounted by hydranths. 



a. Cx)lony large, stem fascicled H. beani. 



b. Colony minute, branches not all in the same plane H. nanum. 



c. (Colony minute, creeping H. repcns. 



B. Female gonangia not surmounted by hydranths. 



a. Stem fascicled H. bermudense. 



b. Stem minute, simple H. ienellum. 



Halecium beani (Johnston). 



Thoa fcf ami Johnston. British Zoophytes, 1847, p. 120. 



Halecium beanii Hincks. Br. Hydroid Zoophytes, 1868. p. 224. Hargitt. American Naturalist. 1901. p. 3S8. 



Halecium beani Nutting, Hydroids of Woods Hole, 1901, p. 358. 



Trophosome. — Colony consisting of a fascicled stem which gives off branches at irregular inter\^als, 

 the largest of these may also be fascicled; these branches may branch again in such a way as to give a 

 zigzag appearance; the branches are divided into intemodes by oblique nodes. The hydrophores 

 are given off immediately below the nodes; not flaring very much; margin often reduplicated. 



Gonosome. — Gonangia borne at the base of the hydrophore; male, regular, oblong-oval; female 

 mitten-shaped, with the aperture at the end of the portion corresponding to the thumb; two hydranths 

 arise from the aperture. 



Distribution. — On red algae floating on the surface, off Bogue Bank. 



The drawing of the gonosome was taken from Hincks as there was no gonosome on the Beaufort 

 material. 



