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



Palpons (PI. XI. figs. l,q, 2, 4; PI. XII. figs. 7-9, q).— The tasters of the Antho- 

 physidae form a simple or multiple corona beyond that of the bracts ; their number is 

 very large but variable, and seems to correspond usually to that of the latter ; it is pos- 

 sible that originally one taster belonged to each single bract, both together composing a 

 medusome (?). The palpon in this case would be the manubrium, and the bract the 

 appertaining umbrella of the medusome. The arrangement of the tasters, too, in the 

 larger Anthophysidse, is very similar to that of the bracts, and the corona of both is 

 bisected by the series of buds (fig. 9, is) placed in the median line of the ventral side. 



The tasters are very long and thin, cylindrical or spindle-shaped tubules, widely 

 protruding through the spaces left between the adjacent bracts when the latter are 

 expanded (PI. XL fig. 1). They are very mobile and flexible, tasting like feelers on all 

 sides. The proximal end of their simple cavity opens into the common stem-cavity, 

 whilst the distal end is closed, and usually armed with a corona of large radial cnidocysts 

 (fig. 4, qc). Sometimes a pigment-spot is visible at the lower side of the distal end, and 

 in Athorybia ocellata this eye-spot seems to surround a small lens or refracting body ; it 

 may be perhaps an ocellus (fig. 4, qo). When contracted, the palpons appear as spindle- 

 shaped or ovate vesicles, hidden in the cavity surrounded by the corona of bracts. There 

 are no palpacles or tasting filaments at the base of the palpons. 



Siphons (PI. XL figs. 1, s, 3 ; PL XII. figs. 7-9, s, fig. 10, longitudinal section). — 

 The number of polypites or siphons in the Anthophysidse is always much smaller than 

 that of the palpons and bracts ; usually the number of the latter may be four to six 

 times as great as that of the former. The smaller species of Anthophysidse have usually 

 only three to six, the larger eight to twelve siphons. These occupy the basal part of the 

 trunk, beyond and inside the corona of palpons, which are much smaller in size. The 

 usual four segments in the body of the siphon are very distinct (figs. 3, 10, longitudinal 

 section). The short pedicle (sp) opens by a narrow canal into the cavity of the trunk. 

 The basigaster (sb) is very large and thick-walled, usually of a yellowish or reddish 

 colour ; the exoderm is much thickened and filled with innumerable cnidocysts. The true 

 stomach (sm) is ellipsoidal, ovate or subspherical, and has a thin exoderm; but the ento- 

 derm- wall is very thick and protrudes inside in the form of numerous conical villi, which 

 contain a variable number of vacuoles or glandular spaces (fig. 10, sv). The proboscis 

 (sr) is very large and extensile; in the contracted state (fig. 10, sr), its muscular wall 

 is very thick, and the eutoderm composed of high cylindrical epithelial cells ; sometimes 

 six or eight longitudinal ribs are visible (fig. 3, sr). The terminal mouth may be ex- 

 panded in form of a large, delicate, polygonal suctorial disc, usually with six or eight 

 triangular lobes (fig. 1, ss). 



Tentacles (PI. XL fig. 1; PI. XII. figs. 11-13). — Each siphon is provided at its base 

 with a long tubular tentacle, which bears a series of tentilla or lateral branches. The 

 form and composition of these tentilla exhibits in the different genera of Anthophysida? 



