236 THE VOYAGE OF H.M.S. CHALLENGER. 



to six times as long as in the contracted state, and as the trunk of the nectosome. It 

 bears twelve to sixteen siphons, and between them very numerous palpons and gonophores 

 scattered along the trunk. The cormidia are, therefore, loose. The entire siphosome 

 is densely covered by innumerable bracts, similar to Cv/pulita and Agalmopsis. 



Bracts (figs. 7, 8). — The hydrophyllia are rather flat and broad scales, ovate or 

 triangular in outline, with a convex dorsal and a concave ventral side. Near the latter 

 a blind bracteal canal (be) runs in the middle line. The proximal end is tapering, and 

 attached by a short pedicle to the trunk. The broadened distal end is provided with 

 three to five short triangular teeth (figs. 1, 3, b). 



Siphons (fig. 3, s). — The polypites are large, and very movable, provided with a 

 long pedicle. The ovate basigaster is narrow. The spindle-shaped stomach exhibits 

 eight hepatic ridges. The cylindrical proboscis opens by a mouth which may be expanded 

 in the form of a large and thin polygonal suctorial disc (fig. 3, ss). 



Tentacles. — The long tentacle which is attached to the base of each siphon, in the 

 constriction between pedicle and basigaster, bears a series of numerous tentilla. The thin 

 pedicles of the tentilla are directed vertically upwards (fig. 1). The cnidosac contains a 

 long purple cnidoband coiled up spirally (fig. 9, tk), and enclosed by an ovate involucre 

 (th) ; the spiral turnings (six to eight) are in the proximal part horizontal, in the middle 

 part oblique, and in the distal part nearly vertical. The terminal ampulla (fig. 9, ta) is 

 ovate, larger than the cnidosac, and encloses in its distal apex an oil-globule, acting like a 

 hydrostatic float. The base of the ampulla is surrounded by a corona of eight slender 

 and very movable radially divergent filaments (fig. 9, tc). 



Palpons. — The entire trunk of the siphosome is covered with scattered palpons, about 

 six to eight between every two siphons. They are slender, spindle-shaped, and very 

 movable tubes, the distal apex of which is armed with cnidocysts. Each palpon (fig. 3, q) 

 bears on its base a long and very thin palpacle, or a simple tasting filament (r). 



Gonodendra. — The corm is monoecious, and the cormidia monoclinic. Numerous male 

 and female gonodendra are scattered along the trunk, about half a dozen between every 

 two siphons, two males and four females. The gonophores are larger and less numerous 

 in the male gonodendra (fig. 3, h) than in the females (/). Their structure, which I could 

 not sufficiently examine, seems not to differ from that of other Agalmidae. 



Family XIV. Forskalid^e, Haeckel, 1 ! 

 Forskalidx, Hkl., System der Siphonoplioren, p. 42. 

 Definition. — Physonectse polygastricae, with a long tubular stem of the siphosome, 

 bearing numerous siphons, palpons, and bracts, each siphon provided with a branched 

 tentacle. Nectosome multiserial, strobiliform, with several spiral rows of nectophores. 

 Pneumatophore with radial pouches. 



