TEREBELLIDAE 



177 



10. 



II. 



Lateral lobes on the first few segments 



No lateral lobes on the first few segments 



Dorsal bristles with denticulated ends ... 



Dorsal bristles smooth ... 



Notopods begin on third segment. Dorsal bristles with denticulated 



Notopods begin on fourth segment. Dorsal bristles smooth 



Prostomium enlarged, lobed. No branchiae 



Prostomium without lobes. Filiform branchiae present 

 Notopods begin on second segment 

 Notopods begin on third segment 



ends 



... 8 

 ... 9 



. Amphitrite 



Polyiniiia 



. Neoleprea 



Nicolea 



. Polycirrus 



... 11 



Streblosoma 



Thelepiis 



Subfamily AMPHITRITINAE 



Tentacular lobe of head not enlarged. Uncini in double rows over a certain number 



of segments. 



Genus Amphitrite, O. F. Miiller 



Two, or more commonly three pairs of branchiae, usually ramified, exceptionally 

 cirriform and arising from a common base. Lateral lobes present in the anterior region. 

 The notopods begin at the fourth segment and the neuropods at the fifth. The bristles 

 have denticulated tips. The hooks are in double rows over a certain number of segments. 



A high dorsal collar on the fourth segment ... ... ... ... ... A. kergiielensis 



No dorsal collar on the fourth segment ... ... ... ... A. affinis, var. antarctica 



Amphitrite kerguelensis, Mcintosh. 

 Hessle, 1917, p. 186, with synonymy. 



Occurrence. St. 599 (i); WS 228 (i); WS 248 (i). 



Specific characters. Three pairs of gills, of which the third pair is attached to a 

 high dorsal collar on the fourth segment. Well-developed lateral lobes on the second, 

 third and fourth segments. About 13 ventral gland shields. The notopods begin on the 

 fourth segment and there are 17 pairs. The bristles are bordered and have denticulated 

 tips. The hooks begin on the fifth segment, and are in double rows from the seventh to 

 the sixteenth unciniger. There are about three rows of teeth above the main fang. 



Amphitrite affinis, Malmgren, var. antarctica, var.nov. 



Amphitrite edwardsi, Monro, nee Quatrefages, 1930, p. 189, fig. 79 a-c. 



Occurrence. St. WS 225 (i); WS 583 (i); WS 765 (3 juv.); WS 785 (3); WS 801 (2); WS 804 (5). 



Specific characters. DiflFers from the stem-form in that the gills are more richly 

 branched, the lateral lobes of the fourth segment are only very slightly developed, and 

 the nephridia extend from segments 3 to 12 instead of from 3 to 8. 



With more material at my disposal I have come to the conclusion that this is a southern 

 variety of the northern and Arctic A. affinis. A fully grown example may measure as 

 much as 120 mm. in length for about 90 chaetigers, but the present form is closer to 

 affinis than to edzvardsi in size. Unfortunately the only specimens in the Museum collec- 

 tion labelled affinis are of little use for purposes of comparison, and I have relied on a 

 comparison of the present specimens with Fauvel's (1927, p. 246, fig. 84 k, I) account 

 of the northern form. 



