POLYCIBBUS. 187 



differentiated into wings, bnt taper to a delicate tip. The setigerous processes bearing 

 them are, in those best developed, lamellar, so that they form a broad brush. 



The succeeding bristles are in smaller pairs, and consist of a series having long 

 straight shafts which dilate into a flattened translucent blade, slightly convex dorsally 

 and tapered to a delicate tip (Plate CXXVI, fig. 10 a). The translucent blade has fine 

 striae and serrations. The tips of shorter forms project from the surface. The flattened 

 tips of the posterior series appear to be modifications of the shorter series in front, the 

 shaft ceasing at their bases, and only a longitudinal streak occupying the centre of the 

 blade. 



The anterior hooks approach those of Ledena, the crowns being large and the bases 

 small. Each (Plate CXXVI, fig. 10 b) shows an acute main fang of moderate size, above 

 which the high crown rises, its anterior edge having about seven distinct teeth. Below 

 the main fang is a small smooth gulf, with a minute conical prow below, the inferior 

 border being convex and rising to a similar small conical process posteriorly, above which 

 is a deep notch, and then the convex posterior border goes to the crown. The posterior 

 hooks do not differ in structure, though less in size, and therein they diverge from many 

 ordinary Terebellids. 



Reproduction. — A mature female occurred in August (Southern). 



Sub-Family II. — Polycikhidea. 



The second sub-family of Malmgren's Terebellidse is the Polycirridea, which he 

 characterises as having an entire and large cephalic lobe, rarely tripartite, the grooved 

 tentacles arising from its upper surface. The bristles are not winged, and, as a rule, 

 occur only anteriorly. Hooks elongate, sublinear or absent. No branchige or eyes. No 

 visible blood-vessels. The genera are thus characterised by Malmgren : 

 No hooks. Bristles in six segments ....... Lysilla, Mgrn. 



in thirteen segments . . Ereutlio, Mgrn. 



in nineteen to twenty-two 



segments .... Leacariste, Mgrn. 



^ in forty or more segments . Polycirras, Grube. 

 Acicular elongate hooks. Fascicles of bristles in ten segments . . Amsea, Mgrn. 



Formerly the group was included under the A/phlebina, De Quatrefages, Grube, 

 Claparede; Polycirrus, Grube, Schmarda; Apneumea and Terebellides abrauches, De 

 Quatrefages ; Ereutho, Malmgren ; Leucariste, Malmgren ; Gyaxares, Kinberg, and 



Avicular hooks. Fascicles of capillary 

 bristles ...... 



Dejoces, Kinberg. 



Genus CLVL — Polycikeus, Grube, 1851. 



Cephalic lobe with a slight dorsal collar, which in extension forms a frilled margin 

 to the funnel-shaped oral region; when folded ventrally it has two lateral flaps with 

 a median furrow. From the surface of this cephalic plate a dense series of grooved and 

 often clavate tentacles springs. Body of the tvpical Terebellid outline, often coiled in 



