SYLLIDAE 99 



The prostomium is broader than long, rectangular and with two pairs of large black 

 eyes. The median tentacle is very long, about five times as long as the prostomium, 

 and arises at the back of the head. The lateral tentacles are about half the length of 

 the median and arise at the sides of the prostomium between the front and hinder pairs 

 of eyes. There are two pairs of tentacular cirri which come off below the head. The 

 dorsal are about the length of the lateral tentacles and twice as long as the ventral. 

 The segment to which they are attached is incomplete dorsally. The first dorsal cirrus 

 is very long, of about the length of the median tentacle, and the following dorsal cirri 

 are about half its length, and the first three or four feet are very small and crowded 

 together. There are no ventral cirri. About the first ten chaetigers and the last forty 

 are without the long swimming bristles : owing to the coiling of the specimen I cannot 

 make an exact count. 



There is a long dorsal cirrus below which in all the middle chaetigers (Fig. 31) 

 is a tuft of long transparent swimming chaetae : below these again is the lobe of the foot, 

 oval in outline and with a notch or incision at its apex just below the ends of the acicula. 

 The compound bristles are numerous, with a short bidentate blade showing a typical 

 Aiitolytiis structure. For the reasons already given I cannot examine the pharynx or 

 make a measurement of the body length. 



Remarks. I have assumed that the broad pouch in this specimen has burst and dis- 

 integrated, for the absence of palps and of ventral cirri, the structure of the chaetal 

 blades and the shape of the dorsal cirri all go to show that this example is a Sacconereis. 

 It may be the female sexual form of Aiitolytus maclearamis of which Ehlers (191 3, 

 p. 492, PI. xxxiv, fig. 3) gives a very brief account and a rather sketchy figure. 



Genus Grubea, Quatrefages 

 Grubea clavata (Claparede). 



Augener, 19 18, p. 295. 

 Fauvel, 1923, p. 296, fig. 114^-^. 

 ? Grubea rhopalophora, Ehlers. 

 Ehlers, 1897, p. 53, pi. iii, figs. 66-70. 



St. WS 25. 17. xii. 26. UndineHarbour (North), South Georgia. 18-2701. Gear BTS. Bottom: 

 mud and sand. Four specimens. 



Remarks. With some hesitation I refer these minute worms to Claparede 's North 

 Atlantic species rather than to the Antarctic G. rhopalophora, because the upper of the 

 tentacular cirri is decidedly longer than the lower. The dorsal cirri are of the gradually 

 tapering fusiform kind, and there is a marked constriction in the pharynx a short 

 distance above the proventriculus. The second tooth on the bristles is exceedingly 

 small and can only be seen at a very high magnification. As Ehlers has noted, there is 

 a considerable variation in the shape of the dorsal cirri in G. rhopalophora. If this 

 extends to the relative lengths of the dorsal and ventral tentacular cirri, the distinction 

 between G. rhopalophora and G. clavata ceases to exist. 



13-2 



