BANSE: REDESCRIPTIONS OF SOME SPECIES OF CHONE AND EUCHONE 



pigment-free areas in the middle of the segments 

 are narrower. The main difference between the 

 specimens from Hokkaido and typical C. ecau- 

 data is the apparent absence of ventral shields, 

 both morphologically and in fully stained spec- 

 imens; the distribution of stain-absorbing cells 

 seems to be uniform ventrally of the setae. In 

 animals where the dye has almost been differen- 

 tiated, however, one does see stronger staining 

 ventrally, and the indication of a whitish line 

 ventral to the parapodia. The Japanese animals 

 are included in C. ecaudata, in spite of the fact 

 that the ventral shields seem to be almost absent, 

 because of the general agreement with the typ- 

 ical form and because of the transitional char- 

 acter of specimens from Alaska (USNM 40723) . 

 Here, the collar is formed as in Japanese mate- 

 rial, but morphologically distinct shields are pre- 

 sent. Staining was not possible. Evidently, 

 additional collections are needed for the study 

 of the Alaskan and northwest Pacific forms. 

 The record of C. teres by Uchida (1968) cannot 

 be identified from the brief description. 



CHONE ENIWETOKENSIS (REISH) 

 NEW COMBINATION 



EUCHONE ENIWETOKENSIS Reish, 1968, 

 p. 225. 



Material studied: Holotype (USNM 38406) 

 and paratype (USNM 38407), from the Mar- 

 shall Islands. 



Diagnosis: A very small Chone species with 

 weakly developed ventral shields and 13 to 14 

 abdominal setigers. Three to four pairs of ra- 

 dicles connected by palmate membrane for one- 

 third of length. Collar oblique. Subspatulate 

 setae with very long pointed tips. Abdominal 

 uncini uniform, with a few teeth; rostra larger 

 than bases. 



Additions to the Description: The collar is 

 higher ventrally than dorsally and has a broad, 

 midventral lowering of the anterior edge. The 

 postsetal girdle of glands is present on the sec- 

 ond thoracic setiger. The holotype, but not the 



paratype, has a similar but somewhat irregular 

 ring also on the fifth setiger. The fifth setiger 

 of the paratype does not appear to be damaged, 

 although otherwise the paratype is somewhat 

 macerated. The ventrum of the thorax stains 

 strongly; however, ventral shields could not be 

 distinguished morphologically. The posterior 

 end is strongly compressed dorso-ventrally sug- 

 gesting, in unstained material, an anal depres- 

 sion. Treatment with methyl green showed un- 

 interrupted segmental rings of staining cells 

 around the posterior ends. 



Remarks: This species is referred to Chone 

 because the posterior end lacks the anal depres- 

 sion typical of Euchone. The species is not yet 

 well characterized; moreover, it is not known 

 whether the specimens were fully grown. If 

 the fifth thoracic setiger indeed carries a glan- 

 dular ring, the species would be uniquely distin- 

 guished. 



CHONE VELERONIS NEW SPECIES 



Figure 7 



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. 0459. 



Paratypes: Same station and date. 

 Poly. 0460 (>10 specimens). 



AHF 



Diagnosis: A small species of Chone without 

 ventral shields, with a greatly broadened post- 

 setal girdle of glands on second setiger. Bran- 

 chial crown long, with very high basis and six 

 to seven pairs of radioles with filiform free ends. 

 Collar low. Palmate membrane reaching beyond 

 distal pinnules. Spatulate setae with pointed 

 tips. Anterior abdominal uncini markedly dif- 

 ferent within tori, largest with small teeth, ros- 

 tra as long as bases; small uncini with greatly 

 enlarged crown. Posterior uncini only of the 

 latter kind. 



The species is named after the present ship 

 of the Allan Hancock Foundation, the Velero IV, 

 which collected the specimens. 



Material studied: About 10 specimens of the 

 type series. 



477 



