272 POLYNOID^E. 



of oysters, and some construct mucous tubes with fragments of shells. Some are phospho- 

 rescent. They described thirteen species of the genus. 



The Polynoidse were included by Kinberg (1857) under his third family, Polynoina. 

 His diagnosis v^as : — Elongated body ; no facial tubercle ; convex cephalic lobe with the 

 base of the tentacle from the middle anteriorly; two antennas; four eyes ; palpi thick. 

 Pharynx exsertile, cylindrical, without long papillae; horny jaws. Scales twelve to 

 thirty-five pairs. Segments bearing elytra devoid of cirri. He gave six genera, viz. 

 Lepidonotus, Halosydna, Antinoe, Harmothoe, Hermadion, and Polynoe, the second, third, 

 fourth, and fifth being new. 



Michael Sars (1860) reviewed the condition of the Polynoida3, as shown by GErsted 

 and the subsequent writers up to date, and gave a list of the northern examples with new 

 species, viz. P. nodosa, P. asperrina, P. rarispina, and P. scabriuscula. 



De Quatrefages (1865) described the Polynoidse as having a very distinct head, 

 furnished with three antennas and four eyes. The buccal segment is characterised by the 

 presence of two pairs of tentacles, the superior being bifurcate, the much longer and 

 larger inferior, simple. The feet are more or less biramous, but the setigeous processes are 

 united to a common base. Elytra alternating with superior cirri, and covering the back 

 throughout. Proboscis armed with two pairs of horny jaws. 



In his remarks on the tribe of the Polynoidse Claparede (1868) l criticises the great 

 increase in the genera caused by Kinberg and Malmgren. Thus the former subdivided 

 the genus Polynoe of Savigny into six, taking as his basis of classification the position of 

 the lateral antennas ; the number of the scales ; the fact of their covering more or less of 

 the dorsum ; and the length of the body. Malmgren again augmented the number of 

 the genera by nearly as many more as Kinberg, so that the original genus of Savigny 

 was multiplied nearly twenty-fold. Claparede points out that the objections of Sars to 

 the methods of Kinberg apply equally to those of Malmgren, because he not only 

 employs the same elements in classification, but adds others of less value, such as the 

 structure of the terminal parts of the ventral bristles. He shows that, for instance, the 

 same species of Syllis presents features which would appear to subvert the reliance to 

 be placed on this method, since the compound bristles are often replaced by simple 

 bristles. There is, however, more in the systematic study of the bristles than Claparede 

 imagined. Claparede grouped the Polynoidas as one of the Tribes of his family Aphro- 

 ditiens, Sav. (sens str.). 



In his supplemental volume he correctly indicated, under Hermadion fragile, the 

 position of the nephridia and their function as channels for the extrusion of the repro- 

 ductive elements. 



Grube, in his ' Annulata Semperiana,' gave the following description of the genus 

 Polynoe. Body oblong or elongated, flattened and vermiform; segments more or less 

 numerous, second, fourth, fifth, and every alternate segment to the twenty-third bearing 

 elytra, the intermediate ones having cirri. The segments after the twenty-third have 

 scales on every third foot or they are absent, rest bear cirri. Cephalic lobe rounded, 

 more or less bipartite; two pairs of sessile eyes, three tentacles, two subtentacles (palpi). 

 Buccal segment with two tentacular cirri, no setse ; two bundles of bristles and two cirri. 



1 Ann. Nap. 



