Gatty Marine Laboratonj, St. Andrews. 30-3 



Pierantoni"^ has also extended tlie list of species of Piono- 

 syllis bearing ova or larvae. His P. gestans lias a series of 

 fourteen or fifteen well-developed larvte along the ventral 

 surface; P. elegans bears eleven or twelve laterally; 

 P. papulosa carries a large ovum on each side for twenty- 

 one segments; whilst P. minuta has fewer ovigeious seg- 

 ments. The dull purplish ova o{ Sphcerosyllis hystnx again 

 are borne below the dorsal cirri. 



In the genus Pionoftyllis is P. serruta, which Southern 

 l)rocured on the west coast of Ireland. It has six eyes, 

 the anterior mere specks at the bases of the lateral tentacles, 

 the middle large, with the lenses directed forward, the 

 j)Osteri()r nearer each other and the lenses directed backward. 

 The body is minute, 2*5 to 3 mm. long with twenty-seven 

 setigerous segments. The anal segment has two slender 

 subulate cirri. The dorsal cirri of the first setigerous segment 

 are the longest of all the appendages. Foot with a bluntly 

 pointed setigerous lobe bearing a small d^rscd papilla at the 

 tip. The bristles have the ends of the shafts enlarged and 

 bevelled, with conspicuous spines, lower bristles simply 

 hooked. Of the sixteen bristles in each foot, five to seven 

 are bifid. 



In Syllis {Typosyllis) variegata, Grube, which Southern 

 distinguishes from P.pruUfera by its colour-pattern, the tips 

 of bristles are less boldly bifid and the edge more serrate ; 

 whilst the spines in the posterior feet are very thick and 

 bluntly pointed, especially in young specimens. 



Streptosyllis websteri, Southern, from the same region, 

 has the feet prominent, five characterising the anterior 

 region, the spine in the first segment being thin as in the 

 posterior segments. In segments 2-5 the spines are large 

 and thick. A single simple bristle is present in the dorsal 

 region throughout. At the sixteenth foot the setigerous lobe 

 is smaller, but the ventral cirrus is longer than in the anterior 

 region. Bristles in segments 1-5 shorter and thicker than 

 in the others. Behind these the bristles are thinner, have 

 serrate terminal pieces, and the end of the shaft is serrated 

 on one edge and has four sharp processes, whilst the spine is 

 slender with a bulbous tip. Capillary bristles begin at the 

 11th segment and extend almost to the tip of the tail in the 

 mature males (the only forms found). 



Southern states that this species is most closely allied to 

 S. varians, De St. Joseph. It resembles it in having five 



* Arch. Zoof. Napoli, vol. i. pp. 231-2o2, taf. 10 & 11 (1911). 

 Ann. cfc Mag. N. Hist. Ser. 9. Vol. viii. 20 



