REPORT ON THE SIPHONOPHORiE. 211 



a number of buds in the uppermost part, beyond the nectophores) a series of a dozen 

 fully-developed cormidia. The internodes of the trunk between these were naked, and 

 had a length of 4 to 5 cm. In the contracted state the trunk was so shortened that the 

 naked internodes disappeared, and the cormidia formed a continuous clustered mass ; 

 the upper part of this was hidden in the space between the ventral grooves of the two 

 nectophores, comparable to a hydrcecium. 



Cormidia (fig. 2). — Bach cormidium is composed of a single siphon with its 

 tentacle ; a single cyston with a palpacle ; a bunch of palpons, each with a palpacle 

 (ten to twenty); a clustered mass of club-shaped bracts (fifteen to twenty -five); and a 

 pair of clustered gonodendra, a male and a female. We may suppose that each bract 

 is the reduced umbrella of a medusome, the manubrium of which is either a siphon, or 

 a cyston, or a palpon : each one is provided with a tentacle or a palpacle. In this case 

 the number of sterile medusomes in each cormidium would be fifteen to twenty-five. 

 The number of sexual medusomes is much larger since the male as well as the female 

 gonodendron is composed of twenty to thirty or more clustered gonophores. 



Bracts (fig. 2, h). — The hydrophyllia, fifteen to twenty-five in each cormidium 

 (besides numerous small buds of young bracts), form together a clustered mass which 

 covers and protects the dorsal or superior side of each cormidium. The form and 

 structure of the bracts are nearly the same as in the common Apolemia. They are 

 club-shaped or pyriform bodies 15 to 25 mm. in length and 10 to 15 mm. in breadth, 

 rounded at the thickened distal end, pointed at the basal end, where they are attached 

 to the trunk by a short mobile pedicle. Their convex outer face is covered with white 

 patches composed of cnidocysts. Near the concave inner face there runs along the 

 median line a simple bracteal canal, which ends blindly near the distal end. 



Siphons (figs. 1, 2, s). — The single siphon, which represents the only feeding person 

 of each cormidium, is rather large, in the expanded state 20 to 30 mm. long and 4 to 

 8 mm. thick. It has a yellowish colour, and exhibits the usual four segments distinctly ; 

 a slender pedicle, to which the tentacle is attached ; a pyriform thick -walled basigaster 

 (sb), the exoderm of which contains masses of thread-cells ; an ovate or spindle-shaped 

 stomach, distinguished by four strong undulate liver-ridges of a red-brown colour (sh), 

 and a muscular proboscis, in the expanded, very contractde wall of which four longi- 

 tudinal muscle-bands can be distinguished (sr). The distal mouth opening may be 

 expanded in form of a broad suctorial disc, which is sometimes circular, at other times 

 provided with four or eight slight mouth lobes. 



Tentacles (figs. 1, 2, t) and Palpacles (figs. 1, 2, >•). — The single tentacle which is 

 attached to the base of each siphon, is a long, simple, cylindrical filament, beset with 

 two longitudinal rows of cnidocysts. It has nearly the same structure as the similar 

 palpacles attached to the cystons and palpons ; these, however, are smaller, much 

 thinner, and less developed (compare above, p. 208). 



