I09 



a long digitiform prolongation, whereas there are four digitiform stylodes along the anterior 

 half of the notopodium. The notopodial fascicle, as usually, consists of simple, whorled bristles. 

 The neuropodium bears on its anterior side a lamella, divided by a fissure in tvvo round lobes; 

 opposite to this fissure lies the distal point of the acicula, beneath which a small oval lobe is 

 visible. On the place where the acicula emerges from the foot, the cuticula is strongly thickened. 

 Also the posterior lamella is divided in two parts, the inferior being narrower than that of the 

 frontal side and the superior lobe is prolonged in a pointed tip. There arise from the dorsum 

 of the neuropodium four digitiform stylodes, whereas in Th. digitata and Th. djiboutiensis the 

 number of these appears to be much greater. The bristle-fascicle consists of the usual bifid setae; 

 those of the upper and lower series have longer appendices, with more joints than the central 

 ones, that consist of two or three joints. In the succeeding segments these many-jointed bristles 

 nearly all disappear and f. i. in the lo"^ segment the neuropodium almost only shows bristles 

 with a short, stout appendix, consisting of a single joint (PI. XXII, fig. 2); in these bristles the 

 distal portion of the shaft is smooth, without spinous rows. The statement, that the difference 

 in the arrangement of the setae in the anterior parapodia, compared to that in the rest of the 

 body, should be a specific character of Th. digitata, as supposed by Willey and Potts, can- 

 not be maintained. About the middle of the body (30"^ segment) there reappear in the upper 

 as well as in the lower series oi, the neuropodial fascicles bristles with appendices, consisting 

 of several joints ; also the shaft beneath the tip is provided with one or two faint ridges. In 

 this body-region there are two large cupshaped ctenidia on the dorsum of the feet and a smaller 

 one in the inner angle of the branchia. In the posterior segments the many-jointed bristles of 

 the neuropodia disappear anew and only those with a simple appendix- remain ; however this 

 appendix is nuich longer and more slender than that in the bristles of the anterior body-region 

 and the shaft in its distal part is provided with three distinct spinous rows (PI. XXII, fig. 3). 

 Also the ventral cirrus grows longer and extends somewhat beyond the distal extremity of 

 the neuropodium. 



On the shore of Haingsisi three incomplete worms were collected, that somewhat differ 

 from the Banda-specimens with regard to their colour as well as to some points of their struc- 

 ture. The red pigment of the elytra shows a reticular arrangement and is accumulated in the 

 neighbourhood of the scar of attachment and of the internal border, thus giving rise to two 

 series of dark spots on both sides of the median dorsal line. Also the anterior part of the 

 dorsum, that is uncovered, till about the 13"^ segment shows the red colour, bordered on each 

 side by a white line. The buccal segment next to the acicula shows a couple of fine bristles 

 and is also provided with a ventral fascicle of slender whorled setae. The second segment is 

 specially distinguished by having more stylodes (9) on its neuropodium than this segment 

 bears in the Banda-specimens ; also the ventral cirrus appears to be somewhat longer, exten- 

 ding beyond the distal extremity of the parapodium. 



Unfortunately we possess detailed descriptions of TJi. digitata and Th. djiboutiensis, and 

 Eittli. insignis only ; therefore it is no easy task to decide wether our specimens belong to a 

 species already described. With regard to the shape of the head they much agree with Th. 

 oculata\ however Th. oculata is considered by Willey as "another form of 77/. «'z^itó/fl, slightly 



65 



SIBOGA-EXPEDITIE XXIV' /(. '5 



