28 THEEL, PRIAPULIDS AND SIPUNCULIDS OF THE SWEDISH ANTARCTIC EXPEDITION 1901 — 1903. 



Phascolosoma anderssoni n, sp. 



Pl. III, tigs. 28—34 and Pl. V, figs. 71 — 74. 



Habitat. — South Georgia: »Sydfjord», Nordenskiöld glaeier, 195 m., clay 

 vvith stones, 29 5 1902. One specimen. »Maj viken», .75 m., clay with algse, 14 /s 1902. 

 Three small specimens. — Mouth of Cumberland Bay, 252 — 310 m., grayish clay with 

 stones. One small specimen. — Gr aham Region, 64° 3' S.— 56° 37' W., 360 m.(?). 

 Four large specimens. 



Total length of the largest specimen more than 100 mm. Body slender, elongate, 

 tapering towards the posterior extremity. Proboscis, when fully extended, nearly as long 

 as the trunk itselj. Tentacles short, obtuse, 21 in number. Skin thin, shining, semi- 

 transparent, covered with small cylindrical papillce and provided posteriorly in front of 

 the extremity with a broad girdle of rather large, conical bladders with their tops directed 

 forward. Hooks absent. Ciliated sense-pads present. Two free segmental organs. Muscular 

 layers of the body-wall continuous and not separated into bands, Two ventral and two 

 dorsal retractors. Intestinal spiral composed of about 24 double tums and not attached 

 posteriorly. Diverticle present. 



The girdle of bladders slightly in front of the posterior extremity of the body 

 gives to the animal a striking appearance. Moreover, in some specimens, that por- 

 tion of the body where the girdle is situated presents itself as somewhat swelled. 

 The bladders are visible to the naked eye, and are closely crowded, thus forming 

 a girdle about 10 mm. broad (figs. 28 and 29). Each bladder is sacciform and more 

 or less distinctly conical with the top directed forward; it bears one or several 

 papillae like those of the remaining parts of the body-wall (fig. 33). The slender 

 tail-like portion of the trunk behind that girdle is covered with small cylindrical 

 papillse which lie more closely together at the end itself (fig. 32). In the transition 

 from the girdle to the tail those papillse rest on broad sack-like bases (fig. 34). The 

 whole surface of the skin carries small cylindrical papillae which are more or less 

 crowded, so that it gets the aspect of being hairy ; at the middle of the body they 

 are more scattered (figs. 30 and 31). 



From the diagnosis it will be seen that the species is devoid of hooks. I 

 counted 21 tentacles (figs. 72 — 74), 11 on the right and 10 on the left side of the 

 median line. Immediately behind the median dorsal tentacles there are two ciliated 

 sense-pads, each of a rounded triangulär shape; they are separated by a median 

 furrow (fig. 73). 



Considering that the Sipunculids in general are in possession of a violent power 

 of contraction, either total or partial, it is almost impossible to state the true length 

 of their bodies or the proportions of their different parts. When fully extended, the 

 species ought to be longer than stated above. The anus opens, most probably, near 

 the middle of the body, and the pores of the two segmental organs seem to have their 

 places immediately in front of that aperture. The dorsal retractors are attached slightly 

 behind the middle of the body and the ventral ones further back (fig. 71). 



