POLYNOIDAE 6i 



Harmothoe (Barrukia) curviseta, n.sp. 



St. i8i. 12. iii. 27. Schollaert Channel, Palmer Archipelago. 64° 20' 00" S, 63" 01' 00" W. 

 160-335 m. Gear OTL. Bottom: mud. One small fragment. 



St. 186. 16. iii. 27. Fournier Bay, Anvers Island, Palmer Archipelago. 64° 25' 30" S, 63° 02' 00" W. 

 295 m. Gear DLH. Bottom: mud. One specimen. 



Description. Two fragments, the larger of which is composed of 24 chaetigers and 

 measures 30 mm. by 10 mm. including the feet: the colour is pale yellow in spirit. 



The prostomium (Fig. 15, a) is as broad as long and divided by a median groove. 

 The insertion of the lateral tentacles is ventral, but the prostomial peaks are not distinct. 

 The eyes are small ; the anterior pair, which is the larger, is far forward and laterally 

 placed, so that it can scarcely be seen from above. The posterior are about in the middle 

 of their half of the prostomium. The median tentaculophore is fairly stout and the 

 median tentacle is lost. The lateral tentacles are small and hirsute, and the palps 

 long, tapering and smooth. Laid along the back they reach to the 5th chaetiger. The 

 tentacular cirri are missing. The first five chaetigers have conspicuous mid-dorsal 

 tubercles, rounded in the first two chaetigers and transversely elongated in the 

 remainder. 



Elytrophores are present on the ist, 3rd, 4th and every alternate segment up to the 

 22nd ; the pseudo-elytrophores are very conspicuous and similar in appearance to the 

 elytrophores. The elytra are dotted throughout with small tubercles with truncated and 

 irregular tops, and except for a small area near the inner border there are long cilia both 

 on the scale itself and along its free edges (Fig. 15, ^). 



The feet are biramous: the dorsal cirri are lost, but the dorsal cirrophores are large, 

 dorso-ventrally flattened structures ending in a rounded knob for the cirrus: they lie 

 above the foot, and their end falls just short of the tips of the dorsal bristles. 



The mid-ventral edge of the dorsal chaeta sac is carried out to a point containing the 

 aciculum, and the middle of the anterior lip of the ventral chaeta sac is similarly pro- 

 duced. The notopodium appears to have been twisted through a right angle, so that 

 the aciculum is in the mid-ventral line, and the dorsal bristles are arranged in three 

 superimposed rows parallel with the long axis of the body. The ventral bristles lie at 

 right angles to the dorsal. 



The upper row of dorsal bristles (Fig. 15, c) is shorter than the rest, strongly curved 

 towards the tip, and provided with rows of prominent pectinae on their convex side. 

 The tips are devoid of hairs. Similar bristles are found in Willey's Gattyatta cristata 

 from Franklin Island, the genotype of Barrukia. The remaining two rows (Fig. 15, </) 

 of dorsal bristles are lightly pectinated, and end in hairy tips, the "setae penicillatae " 

 of Bergstrom. 



The ventral bristles (Fig. 15, e) are slightly more slender than the dorsal, and in place 

 of the usual rows of teeth, there are two short series of two to three teeth. One of these 

 series is always seen lying along the middle of the shaft and the other to its right side. 

 The arrangement is not unlike that figured by Bergstrom (1916, PI. v, fig. 9) for Barrukia 



