REPORT ON THE SIPHONOPHOR^. 181 



sides ; it occupies nearly the ventral half of the subumbrella. It is relatively three 

 or four times as large as the small ovate or lanceolate ventral sinus of the common 

 Hippopodius gleba. (Compare Leuckart, 8, Taf. xii. figs. 1, 2.) 



Siphosome (figs. 1, 7). — The siphosome of Polyphyes ungulata, and its numerous 

 appendages, are very similar to those of the well-known Mediterranean Hippopodius 

 yleba, accurately described by Leuckart (8) and others. An important difference, 

 however, seems to lie in the origin of the clustered gonophores, which are not attached 

 immediately to the base of the siphons (as in the latter), but separated from them by 

 a small interval. The cormidia, therefore, strictly speaking, are not perfectly ordinate, 

 but more or less loose, since the loosely aggregated gonophores alternate with the 

 single siphons. The number of the cormidia is very great in the largest specimens, up 

 to twenty or twenty -five ; besides the numerous small buds of developing cormidia, 

 which are crowded at the top of the siphosome (fig. 7, as). The latter is separated 

 from the top of the deflexed nectosome (an) by a small interval. The trunk of the 

 nectosome is coiled spirally around the proximal portion of the trunk of the siphosome. 



Siphons (fig. 1, s). — -The polypites are in the expanded state about as long as a 

 nectophore, and bear on a small pedicle a subspherical basigaster, followed by a long 

 spindle-shaped stomach ; this passes over into a long and narrow, very contractile 

 proboscis, which opens by the terminal mouth. The mouth is often expanded in the 

 form of a circular suctorial disc (fig. 1 , ss). 



Tentacles (fig. 1, t). — The capturing filament, attached to the pedicle of each siphon, 

 is very long and bears a single series of equidistant tentilla. Each tentillum bears on 

 a long pedicle, which is covered with papillae (fig. 8, tp), a subspherical or ellipsoidal 

 cnidosac, and attached to its base a long simple terminal filament (spirally coiled up in 

 fig. 8, tf). The cnidosac contains a long, nearly annular cnido-battery, following its dorsal 

 convexity, and composed of very numerous, small paliform cnidocysts (fig. 8, km) ; and on 

 each side of it a paired lateral patch, composed of four very large ensiform cnidocysts 

 (fig. 8, M). 



Gonophores. — Attached to the trunk, near the pedicle of the siphon, but separated 

 from it by a small interval, are the monoclinic gonophores. Each cormidium bears in 

 the superior part usually a single large female, in the inferior one or two male, gonophores, 

 besides a small number of buds or younger forms. The male as well as the female 

 gonophores have a well-developed umbrella with four radial canals and a ring-canal, and 

 a large, widely prominent manubrium. That of the androphores (h), or the spermarium, 

 is more oblong, spindle-shaped, and about twice as long as the ellipsoidal ovarium, or the 

 manubrium of the gynophores (f). Usually one larger gonophore of each sex, with a very 

 prolonged manubrium, is prominent from a group of smaller gonophores and of buds. 

 The special structure of the gonophores is the same as in Hippopodius gleba. (Compare 

 above, p. 178.) 



