BANSE: REDESCRIPTIONS OF SOME SPECIES OF CHONE AND EUCHONE 



Broad notopodial lips in thorax. Spatulate setae 

 with pointed tips. Abdominal uncini uniform, 

 with straight crests; small crowns with some 

 small teeth in several columns; rostra not ex- 

 tending beyond bases. 



Material studied: Egedesminde and Godhavn, 

 west coast of Greenland (SMNH 6861; 6862), 

 and Safehavn and Hornsund, Spitsbergen 

 (SMNH 6863; 6864 in part). The material of 

 Malmgren (1866), 8 specimens. 



Greenland, locality unknown. Collected by C. 

 Lutken in the last century, USNM 372, 2 speci- 

 mens. 



Dutch Harbor, Alaska, holotype of Chone 

 teres. PMNH 2761 (previous number: 5-2). 



Additions to the Description: Since the type 

 material from "the Greenlandic sea" is lost (let- 

 ter by Dr. J. B. Kirkegaard, ZMC, 27 Feb. 1970) , 

 excellently preserved Arctic specimens of Malm- 

 gren (1866) are used for additions to the de- 

 scription of the species. The features of the 

 especially suitable specimen from Egedesminde 

 are stressed on the assumption that Kroyer's ma- 

 terial was collected also off the west coast of 

 Greenland where most of the traffic went dur- 

 ing that time. 



The trunks of the smallest specimens are a 

 little less than 2 cm long, are about 1 mm wide, 

 and have about 50 abdominal segments. Large 

 specimens have 70 to 80 abdominal segments 

 and are, when fixed in their tubes, up to 6 or 

 7 cm long (total) and about 3 mm wide. About 

 11/2 cm of the length of the large animals is con- 

 tributed by the branchial crown. The radioles 

 number up to 15 or 16 pairs (up to 22 according 

 to Kroyer, 1856). In addition to the radioles, 

 about half a dozen pairs of inconspicuous nude 

 ventral filaments are present ; the longest ones 

 are almost a fifth of the length of the branchial 

 crown. The palmate membrane extends to two- 

 thirds or three-quarters of the length of the ra- 

 dioles and continues as broad flanges on the 

 radioles. The ends of the radioles are broad 

 and short (Figure la); however, the most 

 ventral pinnated radioles have relatively longer 

 nude tips which are twice as long as shown in 



the figure and sometimes have an additional 

 short filiform end. 



The collar extends dorsally to the end of the 

 second setiger (Figure lb). Thus the furrow 

 separating the first and second setigers does not 

 reach the fecal groove. This character is easily 

 made out. On the ventral side (Figure Ic), the 

 first (buccal) segment is not distinctly sepa- 

 rated from the collar in unstained animals. The 

 body is essentially rounded and entirely covered 

 by glandular tissue, i.e., no ventral shields are 

 present. The glandularization is conspicuous 

 even in unstained specimens. The segments ap- 

 pear as biannulate in the thorax and through the 

 40th to 50th abdominal setiger which is most of 

 the abdomen, by length. Dorsally in the thorax 

 after the second setiger, the intrasegmental fur- 

 rows bend posteriorly before joining the fecal 

 groove. This seems characteristic for the spe- 

 cies; Hofsommer (1913), however, stated that 

 the furrows bend forward. The postsetal glan- 

 dular ring on the second setiger, usually appear- 

 ing in C. infu7idibuliformis as a sunken fine line, 

 is present (contrary to Ushakov, 1955). 



The first bundle of thoracic setae originates 

 slightly dorsad to the level of the notosetae of the 

 following segments. In these segments notopo- 

 dial lips are conspicuous (Figure Id) when not 

 withdrawn. Limbate and spatulate thoracic 

 setae were figured by Malmgren (1866, Plate 28, 

 Figure 87B, B', B^) . Whereas Malmgren depict- 

 ed spatulate setae with and without pointed tips, 

 I have found only setae with pointed tips (Fig- 

 ure le; animals from the four localities of Malm- 

 gren's material); these, of course, are often 

 broken off. In the juvenile specimens, the tips 

 are relatively twice as long as shown here. Bay- 

 onet-type setae have already been observed by 

 Fauvel (1927) for the species. The thoracic 

 uncini are arranged in irregular double rows ex- 

 cept in juveniles; therefore, the oldest (i.e., the 

 dorsal) upper parts of the tori of the adults have 

 only single rows. The abdominal uncini have 

 beaks which do not extend beyond the bases of 

 the uncini (Figures If and Ig; checked also at 

 80th setiger, about 10 segments before the py- 

 gidium). The tips of the accessory teeth lie on 

 the continuation of the rostra. In the anterior 

 segments, these teeth seem to be of uniform size, 



463 



