STAUROCEPHALID^. 351 



neural canal median in position between the cords, dorsal at the ganglia, and occasionally a 

 small one is seen at the side as if from a branch. The cords are comparatively large. 



Grube first established the genus Staurocephalus for the common species 8. rubro- 

 vittatus from Trieste. He afterwards constituted the genus Anisoceros for certain foreign 

 species, which further examination proved to fall under the former genus, and conse- 

 quently this lapsed. In his final publication on the group (1879) he arranged them 

 according to the presence or absence of a terminal segment to the subtentacle and 

 the proportionate length of the latter, the condition of the dorsal cirrus, tentacles, and 

 anterior segments, the eyes and other features being of service in arranging the 

 sub-divisions. 



Kinberg 1 placed this group in the fourth division of his Eunicea, and distinguished 

 it as having the mandibles split, the maxillary series short, and the posterior appendages 

 of the maxillae short. The family itself (Staurocephalea) was characterized by the 

 numerous maxillae, the fourth series being toothed and touching laterally. 



De Quatrefages (1865) included Prionognathus as one of the genera of his Syllids, 

 the type being P. ciliatus, Keferstein, whilst Staurocephalus was placed under genera 

 and species of uncertain position. He thought that the presence of a fine bristle in the 

 dorsal cirrus of Staurocephalus rubrovittatus indicated a bifid condition of the foot, but 

 Claparede argues that the same occurs in Sacconereis helgolandica, Fritz Miiller, in 

 Sigambra Orubei, in Eunice tsenia, and in Psamathe, and therefore thinks its importance 

 exaggerated. 



Claparede (1868) observes that Grube, in his Annulata (Erstediana, constituted the 

 genus Anisoceras for several foreign species which he considered different from Stauro- 

 cephalus already established. But after a study of Anisoceras rubrovittatus he changed 

 the title, making Anisoceras a sub-genus. Unaware of Grube's observations, Keferstein in 

 1862 made a new genus, Prionognathus, for the same type. Fritz Miiller again pointed 

 out the close relationship of the genus with the Eunicidas, and Keferstein's view 

 corresponded, though he linked them also with the abnormal Syllideans. 



The same author (1868) found a dorsal, two lateral and a ventral vessel in 8. Ghiaji, 

 and complex plexuses in the feet, cirri, and tentacles. The lateral and dorsal vessels send 

 forward, the ventral backward currents. 



Levinsen (1883), after Kinberg, grouped the Staurocephalidas as the last of the 

 first section of his Euniciformia, viz., the E. vera, those preceding being the Eunicidas, 

 Onuphidas, and Lumbrinereiclas. It may be presumed that Benham includes the group 

 under his Eunicidas, the tenth family of his Nereidiformia, having in front the Amphino- 

 midas and in rear the Glyceridas, a classification which evoked the criticism of Miss 

 Florence Buchanan, who rightly objected to the author separating Polydora from the 

 Spionidas as an independent family while assimilating the Staurocephalidas with the 

 Eunicidas and placing Spinther, Euphrosyne, and Amphinome under one family. 



Gravier (1900) considers, after Pruvot and Racovitza, that the Staurocephalidas are a 

 more primitive type than the Lumbriconereidas. 



Claparede and Mecznikow 2 (1869) describe a young stage of Staurocephalus Ghiaji, 

 1 Ofvers. Kongl. vet.-Akad. Forlmndl., 1864, p. 574. 

 3 'Zeitsclir. f. wiss. Zool./ Bd.'xix, p. 186, Taf. xv, fig. 3. 



