138 " ENDEAVOUR " SCIENTIFIC RESULTS. 



as observations on species of Eunice tend to show, the segment 

 at which the change of chsetae occurs may probably be quite 

 inconstant. 



hoc. — Forty miles west of Kingston, South Austraha, 30 

 fathoms. 



Distribution. — Ceylon. 



Genus Cheilonereis, gen. nov. 

 The peristomium is produced laterally and ventrally to- 

 form a large, widely extending, collar-like lip {Cheilos=^\i^) ; 

 the base of the notopodium is raised into a lamelhform expan- 

 sion exceeding in height the rest of the parapodium through- 

 out the greater part of the body. 



The type species is Nereis cyclurus, Harrington. i 



Cheilonereis peristomialis, sp. nov. 



(Plate xlvi., figs. 11-18 ; Plate xlvii., figs. 19-22.) 



A single entire specimen of a large species which, like 

 N. cyclurus, Harrington, is characterised by the great develop^ 

 ment of the lower and lateral portions of the peristomium to 

 form a great mobile collar-like lip, which partly covers even 

 the protruded pharynx. It is a broad worm with greatly 

 enlarged lamelliform bases of the notopodia, within the cirri, 

 which with the lamelbform dorsal ligules," give it, at the first 

 glance, a likeness to a Phyllodocid. 



It is a female filled with eggs, which enter the parapodial 

 lobes. The length is 130 mm. for 116 segments ; the greatest 

 breadth is at about the 25th segment, where it is 10 mm. 

 across the body and 13 mm. over the feet ; its height is 8 mm. 

 The diameter increases from 4 mm. at the peristomium to 

 this breadth and then decreases to 8 mm. at about the mid- 

 body, and thence to 2 mm. at the hinder end. 



The prostomium is rather broader than long ; the two 

 pairs of eyes are nearly in line, close to the margin, but 

 the posterior eye is hidden below the greatly developed 

 anterior margin of the peristomium. The tentacles are 

 slender, about half the length of the prostomium, and 

 scarcely reach beyond the tips of the palps. The palps are 

 large, with a small terminal joint, and spring from the lateral 

 region about midway along the prostomium. 



1. Harrington— Trans. New York Acad. Sti., xvi., 1898, p. 219. 



