BANSE: REDESCRIPTIONS OF SOME SPECIES OF CHONE AND EUCffONE 



square base similar to those of many other Chone 

 and Euchone species. The dorsalmost and onto- 

 genetically oldest ones (Figure lid), have a 

 much higher crown with about 10 rows of teeth 

 and are similar to the uncini in the depression 

 segments (Figure lie). 



After staining with methyl green, the pattern 

 on the first setiger agrees with that of E. rubro- 

 cincta (cf. Figure 10c) where the incomplete 

 division of the ventral shield reaches somewhat 

 closer to the midline than that of the second one 

 (Figure 10c, marked by x). 



Remarks: Euchone elegans is close to E. 

 rubrocincta from which it is distinguished by 

 the much smaller number of radioles and their 

 short free ends and the form of the uncini of 

 the anterior abdominal segments. The division 

 of the ventral shield at the level of the first para- 

 podium is marked. The species is also similar to 

 E. analis as described by Malmgren (1866, 1867; 

 cf. p. 482) but has slightly fewer anterior ab- 

 dominal setigers. The posterior abdominal un- 

 cini of E. analis are similar to the anterior ones 

 but are markedly different in E. elegans. 



EUCHONE ALICAUDATA MOORE AND BUSH 



Figure llf-k 



EUCHONE ALICAUDATA Moore and Bush, 

 1904, p. 165. 



Diagnosis: A large Euchone species with 

 ventral shields, with 22 abdominal setigers; 8 

 form anal depression with broad wings. Fifteen 

 to 20 pairs of radioles connected by palmate 

 membrane for one-quarter of their length, with 

 broad flanges extending beyond distal pinnules, 

 and tapering to slender tips. Several pairs of 

 ventral nude filaments. Collar level, with ven- 

 tro-lateral incisions or folds, probably ventrally 

 incised, concealing the branchial basis. Lower 

 thoracic notosetae subspatulate. Uncini of an- 

 terior abdomen with strong necks and bases with 

 posterior extensions; uncini of the posterior ab- 

 domen with high crowns. 



Material studied: Holotype from 280 m near 

 Tokyo. USNM 5496. 



Additions to the Description: The radioles 

 number somewhat more than 15 as stated in the 

 original description ; they end in tips as shown 

 in Figure llf. The collar (Figure llg) appears 

 to have ventro-lateral incisions rather than folds, 

 as originally stated; owing to injury the pre- 

 sence or absence of a marked midventral incision, 

 impHed by Moore and Bush (1904), cannot be 

 verified. A postsetal girdle of glands is present 

 on the second setiger. Bayonet-type setae were 

 not found on the two dissected thoracic noto- 

 podia. In this respect, E. alicaudata is unique 

 among the 25 species of Chone and Euchone I 

 have studied; an investigation of more speci- 

 mens is very desirable. The subspatulate setae 

 were correctly depicted by Moore and Bush 

 (1904, Plate 11, Figure 15). The uncini of the 

 anterior abdomen (Figure llh) have a posterior 

 extension which is not so distinct in depression 

 segments (Figure Hi). The latter, however, 

 have high crowns with 13 to 15 rows of teeth. 



The ventral shields are distinct in thorax and 

 abdomen, becoming even more marked after 

 staining (Figures llg and llj). The shields 

 of the first and second setigers are not com- 

 pletely divided by the intrasegmental furrows. 

 The dorsal thoracic staining pattern is shown 

 in Figure Ilk. In the abdomen, simple broad 

 bands extend from the level of the parapodia 

 across the dorsum except in the segments of the 

 anal depression where the intrasegmental fur- 

 rows disappear. 



Remark: Euchone capensis Day bears some 

 resemblance to E. alicaudata, but the species are 

 well distinguished by the form of the ventral 

 shields on the first (buccal) segment (cf. Fig- 

 ures llg and lln). 



EUCHONE CAPENSIS DAY 



Figure lll-o 



EUCHONE CAPENSIS Day, 1961, p. 540; 1967, 

 p. 776. 



Diagnosis: A Euchone species with ventral 

 shields, with 25 to 32 abdominal setigers; 7 or 8 

 form anal depression. Nine pairs of radioles, 



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