TEREBELLIDAE. 423 



Polycirridea, Artacamacea, Trichobranchidea, and Canephoridea. The endings 

 of these are changed to the standard form for subfamihes, and Canephoridea is 

 replaced by Terebelhdinae to agree with an inchided genus and .Vmphitritea 

 by Terebellinae. 



Clu-istian Hessle (Op. cit. 1917) unites the Artacaminae with the Terebellinae 

 (Amphitritinae) and erects a subfamily Thelepinae for Thelepus and some 

 related genera, this being characterized by having the uncini throughout in 

 single rows as in the Polycirrinae, the nuchal organ developed, the tentacle- 

 bearing region not widened, and the branchiae consisting of simple filaments 

 arranged in cross-rows. In separating genera Mahngren placed too great reliance 

 upon the number of setigerous fasciae, these being in the main too variable for 

 generic differentiation by themselves, as shown by Marenzeller (Sitzungsb. K. 

 akad. wissensch. Wien, 1884, 89, p. 152-214) and St. Joseph (Ann. sci. nat. 

 1894, ser. 5, 17, p. 166). As to the branchiae, great care must be taken in relying 

 upon them, since the number may vary with age in one and the same species of 

 certain genera {e.g., Amphitrite). Much importance is to be attached to the 

 structure of the setae, and particularly the detailed structm'e and arrangement 

 of the uncini. But even upon the basis of these characters the separation of the 

 genera may be a matter of difficulty and delicacy since certain variations may 

 likewise occur in the uncini with change in age, as noted for instance in Loimia 

 medusa Savigny by Gravier (Nouv. arch. Mus. hist, nat., 1908, ser. 4, 10, p. 224, 

 text fig. 396-399). 



Synonymy of Genera. 



Laphaniella Mahngren is apparently to be included in Leaena Mahngren. 



Scionopsis Verrill is synonymous with Pista Malmgren. 



Idalia Quatrefages and Axionice Malmgi-en are also here included in 

 Pista Mahngren. 



Grymaea Malmgi-en and Streblosoma Sars are synonyms. Grymaea has 

 the priority but is preoccupied, and so Streblosoma must be used. 



PhyseUa or, as also written, PhyzeUa, Quatrefages included species of 

 Amphitrite, Pista, and Nicolea. 



Scione Malmgren (1865) is preoccupied by Scione Walker (Dipt., 1856). 

 Hence it is here replaced by Euscione, nom. nov. 



Thelepides Southern (1914) is preoccupied by Thelepides Gravier (1911). 

 It is replaced by Parathelepus Caullery (1915). 



