BANSE: REDESCRIPTIONS OF SOME SPECIES OF CHONE AND EUCHONE 



25/. 



d,e 



Figure 4. — Chone gracilis, from holotype: a, end of median radiole. Origin of pinnules 

 indicated schematically; b, dorsal view of anterior end, branchial crown omitted; c, 

 ventral staining pattern of anterior end of trunk; d, spatulate seta from sixth setiger; 

 e. uncinus from third abdominal setiger. 



dioles connected for three-fifths of length by 

 palmate membrane, with free ends gradually 

 tapering to pointed tips. Branchial basis as high 

 as collar; collar almost level, with distinct ven- 

 tral indentation. First bundle of setae of normal 

 size, inserted at same level as following noto- 

 setae. Rounded notopodial lips in thorax. Spat- 

 ulate setae with long pointed tips. Abdominal 

 uncini uniform, with small accessory teeth in 

 several columns; rostra not extended beyond 

 bases. 



Material studied: Holotype, from Kodiak 

 Island (originally spelled Kadiak) , southwestern 

 Alaska. USNM 5513. 



Additions to the Description: The original 

 description of the specimen, a mature female, 

 was rather complete but was accompanied only 

 by a few figures so that there has been some 

 confusion with other species. The branchial 

 basis is as high as the collar. A tip of a median 

 (lateral) radiole is shown in Figure 4a. The 

 collrr (Figures 4b and 4c) inserts dorsally on 

 the anterior part of the second setiger. The free 

 dorsal edge of the collar is folded inwards as 

 stated by Moore (1906) . The edge rises ventro- 

 laterally and ventrally slightly over the height 

 attained dorsally. A midventral indentation of 

 the collar is very conspicuous. The first (buccal) 

 segment is distinct ventrally even without stain- 

 ing. The intrasegmental furrow on the second 



setiger reaches the fecal furrow. A postsetal 

 girdle of glands is present on this setiger. The 

 first bundle of setae, now preserved on only one 

 side, is of ordinary relative size and inserts at the 

 same level as the notopodia of the following seg- 

 ments. Moore (1906, Plate 12, Figure 62) de- 

 picted bayonet-type setae without designating 

 them as such. The spatulate setae (Figure 4d) 

 have unusually long tips as shown also by Moore 

 (1906, Plate 12, Figure 64). The abdominal 

 uncini (Figure 4e) are uniform throughout and 

 have about six rows of approximately six small 

 teeth which are difficult to count. Upon staining 

 with methyl green, thorax and most of the ab- 

 domen turn uniformly green excepting the in- 

 tersegmental and intrasegmental furrows; also, 

 the presetal parts of the segments dorsal in the 

 thorax are paler than the postsetal parts. Ven- 

 trally, the incomplete anterior and posterior bor- 

 ders of the first segment are distinct. The intra- 

 segmental furrow of the first setigerous segment 

 is poorly visible. 



Remarks: I concur with Moore (1906) that 

 this is a species of its own ; it is distinct from 

 C. infundibuliformis (contrary to Pettibone 

 1954). Based on his description and the obser- 

 vations provided here, C. gracilis is distinguished 

 among the species with glandularized epidermis 

 by its ventrally indented collar; another diag- 

 nostic character is the combination of a relatively 

 long branchial crown which contributes more 



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