FISHERY BLLLETIX: \0L. 70. NO. 2 



Additions to description: Because the species 

 is well known, only some characters have been 

 studied, mostly for a comparison with E. capensis 

 Day and E. velifera new species, both of which 

 also have collars with ventral incisions. The 

 animals studied were fixed in their tubes, are up 

 to 2.5 cm long, and are well preserved. 



The radioles have free filiform ends as shown 

 by Malmgren (1866, Plate 29, Figure 92G but 

 not 94G). The collar (Figure 9d) is markedly 

 longer ventrally than dorsally. The number of 

 abdominal segments in six animals is 21, 21, 22, 

 23, 23, and 24, of which 8 to 10 form the anal 

 depression. Similarly Hofsommer (1913) found 

 specimens from the western Baltic, which he be- 

 lieved to be juveniles, with a total of 29 seg- 

 ments ( = setigers, from the context) and stated 

 that in adults the number is constantly 35, sim- 

 ilar to Malmgren (1866). Evenkamp (1931) 

 in material from Kiel Fjord, however, observed 

 up to 62 segments of which, again, 8 were tho- 

 racic. 



Thoracic notopodia contain broad bayonet- 

 type setae (Figure 9e) and spatulate setae (Fig- 

 ure 9f). The spatulate setae in the present 

 material are broader than those depicted by 

 Malmgren (1866, Plat 29, Figures 926^ and 

 94B^). The uncini on anterior abdominal seg- 

 ments (Figure 9g) have broad bases with small 

 posterior appendages and crowns with approxi- 

 mately 10 columns with 10 to 13 teeth each, de- 

 pending on the size of the uncini. Posteriorly 

 in the abdomen, the bases of the uncini become 

 more rounded, and there are about 15 rows of 

 teeth in much enlarged crowns (Figure 9h). 



The thoracic and abdominal ventral shields are 

 very conspicuous even in unstained material 

 (cf. Malmgren, 1866, Plate 29, Figures 92 and 

 94) . After using methyl green, the ventral pat- 

 tern in the anterior thorax is as shown in Figure 

 9d. Laterally in the thorax, crescentic areas of 

 stained tissue occur posterior to the parapodia 

 and to a lesser degree anterior to them. The 

 dorsal side of the thorax is unstained except for 

 a pair of conspicuous rounded areas near the an- 

 terior border of each segment from the 4th se- 

 tiger onwards. In the anterior and middle re- 

 gions of the abdomen, each setiger shows 

 ventrally two pairs of rounded patches, one near 



the anterior and one near the posterior border. 

 These have been figured first by Malmgren 

 (1866, Plate 29, Figures 92 and 94) . Their size 

 varies among individuals; they sometimes oc- 

 cupy almost half of the ventral area of the seg- 

 ments. Laterally in the abdomen, the stained 

 tissue around the parapodia, observed in the 

 thorax, becomes gradually larger and extends 

 onto the dorsal side so that from the middle of 

 the abdomen, a pigmented band crosses the pos- 

 terior part of the segments (the parapodia in- 

 sert here posteriorly on the segments) . In the 

 same region, the anterior dorsal patches coalesce. 

 Shortly before the depression segments, the in- 

 trasegmental furrows disappear and each seg- 

 ment is uniformly stained both dorsally and 

 ventrally. 



EUCHONE RUBROCINCTA (SARS) 



Figure 10 



CHONE RUBROCINCTA Sars, 1862, p. 128. 



EUCHONE RUBROCINCTA.- Malmgren, 1866, 

 p. 406.- Southern, 1914, p. 144.- Mcintosh, 

 1916, p. 33; 1923, p. 282.- Southward, 1956, 

 p. 278. 



Diagnosis: A Euchone species with conspic- 

 uous ventral shields, with 11 to 15 anterior ab- 

 dominal setigers and up to 12 setigers in anal 

 depression. Up to 16 pairs of radioles united 

 by palmate membrane for about half their length, 

 with long free ends. Up to eight pairs of nude 

 filaments. Collar level, with a small ventral 

 notch. Lower thoracic notosetae subspatulate. 

 Uncini of anterior abdomen with small crowns of 

 teeth, slim necks, and narrow bases with marked 

 posterior extensions. Uncini of posterior abdo- 

 men with large crowns, without necks. 



Material studied: Syntypes, from Floro, near 

 Bergen, Norway, approximately lat 61°40'N, 

 long 5°00'E, stony bottom (Sars, 1862). ZMO, 

 3 specimens. 



Ballynakill Harbour, Northwest Ireland, sta- 

 tions L 245, L 310, and ML L 11a (cf. Southern, 



484 



