112 AMPHITRITB AFFINIS. 



are well marked, the former showing a slight dilatation of the shaft at the commencement 

 of the wings and a long, curved, tapering, serrated tip. The shorter bristles have a 

 proportionally stouter shaft, with a distinct twist or bend in the flattened blade after the 

 wings cease, the tips thereafter being finely tapered. 



The branchiae arise from a short stem, and split up into a number of branches, each 

 dividing into two, the whole forming a dense tuft. 



The anterior hooks (Plate CXXXVIII, figs. 6) have a more erect character 

 than those of A. cirrata, and the slope made by the base comes nearer a right angle, 

 whilst the hollow in the posterior outline is median, not near the inferior angle as 

 shown by Malmgren, so that the Canadian form may differ, whereas that procured in 

 the " Porcupine " more nearly corresponds. There are five or six teeth above the main 

 fang. The posterior hooks (Plate CXXXVIII, fig. 6 a) have a more erect figure, with 

 a shorter and more massive base. 



Hessie (1917) places this under his genus Neo-amphitrite, but the distinctions do not 

 appear to be such as to warrant the complication. 



3. Amphiteite affinis, Malmgren, 1865. Plate CXX, fig. 10 — branchia; Plate CXXV, 



figs. 6 — 6 b — bristles and hook. 



Specific Characters. — Body typical. Anterior region presents a transverse shield 

 behind the mouth, passing dorsally to join the smooth area in rear of the collar. Eleven 

 shields follow besides several rudimentary. The dorsal edge of the second segment 

 extends to the base of the first branchia, whilst the dorsal edge of the third falls short 

 of its branchia. A still longer gap separates the first bristle-tuft of the next segment from 

 the third branchia. Behind the shields a deep groove occupies the ventral median line. 

 Branchiae three, on second, third and fourth segments, small, and with rather short and 

 thick terminal divisions. Seventeen pairs of setigerous processes, the first opposite the 

 third branchia. Bristles pale golden, the tip having narrow wings, which soon cease, 

 the translucent region beyond being flattened like a long knife-blade, serrated on the 

 edge, and tapered into a very long hair-like extremity. Hooks in a double row, each 

 having a small base and a large neck and crown, with three teeth above the main fang, 

 in lateral view, and a process in the gulf below it. It is distinguished from the hook 

 of A. cirrata by the fact that the posterior outline more nearly forms a right angle with 

 the base, the angle being more obtuse in A. cirrata. 



Synonyms. 



1865. Amphitrite affinis, Malmgren. Nord. Hafs.- Annul., p. 375, Tab. xxii, fig. 55. 



1867. „ „ idem. Annul. Polych., p. 107. 



1883. „ „ Wiren. Chaatop. " Vega » Exped., p. 419. 



„ „ „ Levinsen. Yid. Meddel. Nat. Forh. Copenhagen, p. 174. 



1894. „ » Bidenkap. Christ. Yid. Forh., No. 10, p. 128. 



1912. „ „ Wollehask. Skrift. Selsk. Krist., Bd. ii, No. 18, p. 101, pi. xxxiv,figs. 1—7. 



1913. „ „ Augener. Zool. Anz., Bd. xli, p. 268 (Franz- Joseph Land). 



1914. „ „ Southern. Proc. Roy. Irish Acad., vol. xxxi, No. 47, p. 121. 



1915. „ „ Mcintosh. Ann. Nat. Hist., ser. 8, vol. xv, pp. 9 and 44. 

 1917. Neoamphitrite affinis, Hessie. Zool. Bidrag Uppsala, Bd. v, p. 179. 



