PIONOSYLLIS PROLIFEPA. 163 



reddish eyes, and its foot is shown in Plate LXX, fig. 5. Moreover, in a female bud 

 with swimming-bristles, from the West Voe of Burra, Shetland, the falcate bristles had 

 stouter shafts and shorter terminal pieces (Plate LXXVTII, fig. 14 6). Some of the 

 female buds in Shetland were of a pale lilac hue. 



At first sight amongst the rocks this widely distributed species somewhat resembles 

 S. armillaris. It is easily discriminated by the longer dorsal cirrus, the structure 

 of the bristles, and the longer ventral cirrus. It is a characteristic species of the 

 southern shores of Britain, and if it is right to make Pionosyllis Malmgreni a variety of 

 the same form, then it is sparingly represented on the west so far north as the Outer 

 Hebrides, and it may occur so far as Shetland. 



A form which was found between tide-marks in Herm differs from the ordinary 

 examples in the shortness of the dorsal cirri, which have only ten articulations (Plate 

 LXX, fig. 6) . Moreover, in certain varieties, as in one from Luccomb Chine, a calcareous 

 region, the bifid tip of the bristle is less evident (Plate LXXVIII, fig. 16). 



Krohn (1852) first discriminated this species when describing its budding and that 

 of Autolytus prolifer, and it is quite recognizable from his account. He also alludes in a 

 footnote to an allied form which he termed Syllis fissipara. 



Grube (1863) described the same species from Xeresine in the Adriatic as Syllis 

 lussinensis, giving characteristic figures of the anterior segments and bristles. 



The Syllis fiumensis of Ehlers (1864), though he describes and figures the terminal 

 region of the bristles as simple, appears to be this species. He gives a detailed account 

 of the alimentary canal with good figures, and also describes the segmental organs and 

 the budding. 



The same year (1864) Claparede described and figured his Syllis Armandi as 

 common at Port-Vendres, giving an account of the general structure and reproduction. 

 His figure of the bristle is indifferent. 



Marenzeller (1874) found this species plentiful in the Bay of Muggia. It was of a 

 brownish-violet colour, with bands anteriorly and a speck at the base of t\\e dorsal cirrus. 

 The intestine shone through the tissues as a brownish-green streak, and the posterior end 

 of the body was yellowish-green. Anteriorly the dorsal cirri are alternately long and 

 short. His figures of the tips of the bristles are good. A bud arose from the forty-eighth 

 segment, with capillary swimming-bristles. He recognized its relationship with Krohn's 

 S. prolifera. 



Langerhans (1879) mentions and figures a simple bristle with a bifid tip which he 

 found from the twentieth to the thirtieth segment. He also observes that the budding 

 takes place in the following segments, viz. 31, 33, 35, 36, 37, 41. 44, and that the ova are 

 greenish. Vorticellds are frequently parasitic on it. 



De St. Joseph (1888) observed that in the stoloniferous examples violet ova or 

 sperms occurred in two or three segments in front of the bud according as that was male 

 or female. He mentions a male bud as rose-orange, and points out that the Ghxtosyllis of 

 Malmgren l is a closely allied bud. He also describes one which had a regenerated head. 



The variety described as Pionosyllis Malmgreni, from Lochmaddy, shows no bars in 



, l ' Annul. Polycli./ p. 162, Tab. ix, fig. 51. 



