126 DISCOVERY REPORTS 



Genus Trypanosyllis, Claparede 

 Body flattened and ribbon-like. Palps clearly separated. Dorsal cirri moniliform. 

 Pharynx with a crown of teeth and a single anterior tooth. Reproduction by stolons. 



Bristles unidentate. Body colourless T. gigantea 



Bristles bidentate. Body striped T. taeniaeformis 



Trypanosyllis gigantea (Mcintosh) (Fig. i8). 



Syllis gigantea, Mcintosh, 1885, p. 193, pi. xxx, figs. 1-3; pi. x.xxiii, fig. 4; pi. XA, fig. 14; 

 pi. xxivA, fig. 7. 



Trypatiosyllis gigantea, Ehlers, 1901, p. 85, pi. vi, figs. 11-16. 

 Benham, 1927, p. 56, pi. i, fig. i. 

 Occurrence. St. 652 (i); WS 85 (i); WS 225 (11); WS 228 (i); WS 244 (2); WS 246 (3); 

 WS 248 (3); WS 249 (i); WS 783 (i); WS 785 (2); WS 803 (2); WS 804 (2); WS 825 (i); WS 847 

 (i);WS 877(1). 



Specific characters. A large flattened, ribbon-Uke species measuring up to 200mm. 

 in length. There are no colour markings except on the longer dorsal cirri, which are lilac. 

 The head is bilobed and deeply incised behind. There 

 are two pairs of large eyes. The median tentacle is about 

 four times as long as the head, and the laterals about two- 

 thirds of this. The dorsal tentacular cirrus is about a third 



as long again as the median tentacle and the ventral ten- pjg jg Trypanosyllis gigantea. 

 tacular cirrus about one-half of this. The pharynx is Ventral view of head of stolon. 

 thickly lined with chitin and has a crown of about 



12 teeth, and also a single terminal pharyngeal tooth. This crown is surrounded by a 

 circlet of 10 large papillae. In the anterior and posterior regions the longer of the 

 alternating dorsal cirri are about two-thirds as long as the body is broad, and in the 

 middle region they are equal to about half the breadth of the body. The shorter dorsal 

 cirri are about two-thirds of the length of the longer. The feet are more or less lanceolate 

 and are supported by three or four acicula. The bristles are unidentate. The ventral 

 cirri are conical. 



Remarks. Two examples collected in September 1928 are in the "chain" phase. 



As in T. zebra, observed from the dorsal surface the stock and the stolons appear to be 



in complete continuity, and stolonization can be detected only from the ventral surface. 



The two specimens exhibit diflFerent stages in stolonization, an earlier and a later. 



In the earlier stage the stolons, of which there are five, begin at the 200th segment. 



All that can be seen is on the ventral side a very narrow transverse ridge of tissue, with 



a pair of rudimentary tentacles at its outer edges, interrupting the continuity of the 



segments. The stolons have about 25 chaetigers. At this early stage I find it difficult, 



without sectioning, to discover the sex of these buds. I have seen no eggs. A little later 



stage (Fig. 18) is represented by the greater development of the pair of tentacles and by 



the appearance of a pair of eyes below the ventral cirri of the segment following the 



transverse ridge of tissue. In this specimen the stolons begin at the 290th chaetiger, 



and have 18 segments. Here again I can see no eggs. 



