Clare Island Survey — Archiannelida and Poltjchaeta. 47 21 



the length. It has 4 large eyes, with reddish- brown pigment, provided with 

 lenses. 



The tentacles, tentacular cirri, and dorsal cirri resemble those of Sphaero- 

 syllis hystrix, being flask-shaped with a globular base and cylindrical distal 

 portion. The palps are long and broad, completely fused, with a faint dorsal 

 furrow, and a broad and conspicuous ventral groove. Between the head 

 and buccal segment in the lateral region are the conspicuous ciliated nuchal 

 organs (fig. 2c). The buccal segment is quite distinctly separated from the 

 head, though narrower than the subsequent segments. The anal segment 

 (fig. 2b) bears a number of small papillae, and two long cylindrical cirri, with 

 slightly swollen bases. 



The parapodia are all similar. The dorsal cirri of the second setigerous 

 segment are missing, as in all species of the genus Exogone. The setigerous 

 lobe is short and bluntly rounded (fig. 2d), the dorsal cirri are flask-shaped, 

 the ventral cirri small and cylindrical. The setae in each segment are 

 very similar. In the dorsal region of the foot there is a stout simple seta 

 (fig. 2e, b) slightly curved at the tip. It is usually present in all the feet, 

 and is thicker in the middle of the body (fig. 2f, b). In the anterior segments 

 it narrows suddenly, and is slightly hispid at the tip. In the terminal 

 segments it is rather different in shape (fig. 2g), with a bolder curvature and 

 gradually pointed tip. In a variable number of the posterior segments, in 

 some cases only 4, in others as many as 20 segments, there is added a similar 

 ventral simple seta. The compound setae are few in number, usually 4 in 

 each foot, and have slightly curved shafts, bevelled at the tip, with a distinct 

 shoulder (fig. 2e, a). The terminal pieces are all short, approximately equal 

 in length, with a simple tip, and serrate edge. In the posterior segments, 

 the tip of the shaft is more spinous than in the anterior segments (fig. 2f, a), 

 and the serrate edge of the terminal pieces seems to have been worn away. 

 The spines (figs. 2e, 2f, e) are stout, with a bulbous tip, terminated by a 

 small papilla, differing greatly from the bent tip in Sphaerosyllis hystrix. 

 The proboscis (fig. 2a) stretches through four segments. It has a bluntly 

 rounded tooth in front, and a crown of soft papillae. The proven triculus 

 occupies two segments, and has 14 rows of glands. Two small diverticula 

 are attached to the front end of the intestine. 



This species is characterized by the absence of papillae on the body, the 

 large palps, the short terminal pieces of the setae, the structure of the simple 

 setae and spines, and the well-developed buccal segment. It is closely allied 

 to Sphaerosyllis Gla r paredei Ehlers (Borstenwiirmer, p. 252) ; but in the latter 

 species the buccal segment is completely fused with the head, and there are 

 no papillae on the feet or anal segment, besides ocher small differences. 



