BANSE: REDESCRIPTIONS OF SOME SPECIES OF CHONE AND EUCHONE 



abdominal setigers. The pygidium is triangular 

 and pointed. Eggs occur from the sixth thoracic 

 setiger. 



The inconspicuous first bundle of setae orig- 

 inates at the level of the following notopodia. 

 These have four to six of each upper limbate, 

 very tiny bayonet, and pointed spatulate (Fig- 

 ure 7d) setae. Notopodial lips were not seen. 

 Thoracic neuropodia contain slightly more than 

 half a dozen long-handled uncini (Figure 7e). 

 Abdominal setigers carry approximately half a 

 dozen finely limbate neurosetae and, at least 

 through the 40th setiger, 12 to 15 uncini. The 

 uncini from the anterior abdomen, in the most 

 recently formed sections of the tori, are of the 

 usual form of Chone (Figure 7f) with several 

 columns of five to six accessory teeth each. The 

 smallest, i.e., oldest, uncini of these tori, and all 

 uncini in posterior segments (Figure 7g), have 

 smaller bases and appear similar to the uncini 

 of Orlopsis. The posterior uncini have about 

 six columns of about seven teeth each. 



Staining with methyl green shows the absence 

 of ventral shields. The whole surface in the an- 

 terior half of the body accepts the dye uniformly 

 except for the anterior edge and ventral parts 

 of the collar (cf. Figure 7a) , the inter- and intra- 

 segmental furrows, and the glandular girdle on 

 the second setiger. Ventrally, the anterior bor- 

 der of the first setiger, which is often invisible in 

 unstained material, is marked as a whitish line. 

 The presetal rings of glandular tissue stain less 

 well than the rest of the epidermis. On the 

 posterior half of the abdomen only few epidermal 

 cells accept the stain. 



Remarks: Hartman (1959, 1965) has listed 

 the species of Chone, to which C rosea Hart- 

 mann-Schroder, C. striata Hartmann-Schroder, 

 C. trilohata Gallardo, and C. alhocmcta described 

 below should be added. Among these, C. velero- 

 nis is distinguished by the ventral enlargement 

 of the postsetal glandular girdle on the second 

 setiger, the very long branchial bases, and the 

 length of the palmate membrane. Only very 

 few species (e.g., C. are^t/coZft Langerhans) have 

 a palmate membrane extending beyond the origin 

 of the distal pinnules. 



CHONE ALBOCINCTA NEW SPECIES 



Figure 8 



Holotype: From Velero station 6104, lat 

 33°39'45"N, long 118°06'40"W, 26 m, dark gray 

 silty fine sand, 19 Feb. 1959. AHF Poly. 0454. 



Paratypes: From same station and date. 

 AHF Poly. 0455, three adults or near-adults, nine 

 juveniles. 



Diagnosis: A Chone species of intermediate 

 size without ventral shields. Branchial basis 

 slightly longer than the slightly oblique collar. 

 Eight to ten pairs of radioles, connected by pal- 

 mate membrane up to origins of distal pinnules, 

 with abruptly tapered filiform free ends. Pre- 

 setal whitish rings of tissue in thorax ; presetal 

 and postsetal whitish rings in anterior and me- 

 dian abdomen. First bundle of setae small, on 

 same level as following notosetae. Spatulate 

 setae with pointed tips. Anterior abdominal 

 uncini markedly different within tori, smallest 

 with rounded bases and high crowns. Posterior 

 abdominal uncini predominantly of latter type. 



The name of the species refers to the whitish 

 rings contrasting in unstained animals with the 

 red-brown color of the remaining epidermis. 



Material studied: Type series. 



Description: The holotype is a mature female 

 with 8 thoracic and approximately 50 abdominal 

 setigers. The total length is about 18 mm, the 

 greatest width is 1 mm. The branchial crown 

 measures about 6 mm. Two other adult animals 

 of 51 and 52 abdominal setigers are slightly 

 larger (total 20 mm; branchial crown, 7 mm) 

 and somewhat shorter than the holotype. The 

 juveniles have trunks about 5 mm long and the 

 same body proportions. All specimens are well 

 preserved. 



The branchial crown has a base slightly longer 

 than the collar and 9 to 10 pairs of radioles which 

 are united by the palmate membrane up to the 

 insertion of the distal pinnules. A 0.2-mm broad 

 flange extends for a short distance beyond this 

 point but tapers abruptly to a filiform free end 

 (Figure 8a). The free ends of the radioles are 



479 



