85 



Two specimens (badly preserved and discoloured) were found by Dr. van Kampen in 

 holes in the arm-pits of an Asteroid. 



Genus Lepidasthenia Malmgren '). 



Body elongate. Elytra numerous, minute, leaving the greater part of the dorsum unco- 

 vered, inserted upon segments 2, 4, 5, 7 .... 23, 26, 29 to the end. Notopodial fascicle absent 

 or rudimentary ; in the neuropodial fascicle sometimes the upper setae enlarged or slender. 



I. Lepidasthenia affinis n. sp. PI. XIX, fig. 8. 



Stat. 33. Bay of Pidjot, Lombok. Depth 9 to 22 M. 2 specimens. 



At this Station two specimens (a complete worm and an anterior body-fragment) were 

 collected, that belong to a species undoubtedly closely allied to Lepidasthenia elegans (Gr.)-), 

 with which they agree in the presence of one or two stout bristles with single apex and 

 reduced spinous rows in the dorsal part of the neuropodial fascicle. Unfortunately we do not 

 possess a sufficiënt figure of the bristles of this mediterranean species ; only VON Marenzeller 

 figured some bristles of the immature worm {Polynoe lamprophthalmaY) and Potts published 

 a sketch of the parapodium of Lepidasth. elegans from Zanzibar*), considered by him as a 

 Southern form of the mediterranean species. A typical parapodium (f. i. the 13"^) of the Siboga- 

 worm contains four kinds of neuropodial setae (PI. XIX, fig. 8): i" the true Zg/za'ö.y//;^«?«-bristles 

 with bifurcated tip and a row of striated lamellae on each side of the subterminal dilated part 

 (fig. 8 d) ; 2° the inferior setae, distinguished from the first group by their slender appearance, the 

 spiniferous part that is bent backward and the apex (above the spur) that is thickened and obtuse 

 (fig. 8 5) ; 3" two stout dorsal bristles, larger than those of the first group, with a single apex (or 

 minute spur) and reduced lamellae (fig. 8^); 4° two slender setae, situated dorsally, faintly bent, 

 with elongated spiniferous area and a tip, that is obtuse or hardly bifurcated (fig. 8 d). In the seg- 

 ments situated more posteriorly the upper slender bristles disappear and the two stout setae 

 of the third group become larger and thicker, whereas the inferior of both acquires a dark brown 

 colour. Anteriorly those stout bristles are visible in the vicinity of the 10* segment, whereas 

 Potts states regarding his Lepidasth. elegans: "anterior to the twenty-first segment the 

 superiority of the uppermost setae is not distinctly marked posteriorly". The scales are roun- 

 dish, without cilia on the margin, with a spot of black pigment on the scar of attachment, 

 which is situated somewhat eccentrically ; there are more than 40 pairs of them. They are not 

 so small as in Lepidasth. elegans and do not decrease posteriorly; therefore they leave only a 

 narrow part of the dorsum bare in the anterior body-region and in the posterior segments 

 they somewhat overlap each other. Von Marenzeller states that in an adult Lepidasth. elegans, 

 broad 3.9 mm. (from the right to the left elytrophore), the elytron measured 0.75 to 0.80 in 



i) Annulata Polychaeta Spetsbergiae etc. 1867, p. 15. 

 2) GrUBE, Actinien, Echinodermen vind Würmer, 1S40, p. 85. 



3j Zur Kenntniss der Adriat. Anneliden, I; Sitzungsber. Acad. d. Wissensch. Wien, Math. Naturw. Classe, Vol. LXIX, 1874. 

 PI. I, fig. I. 



4) Loc. cit. PI. 20, fig. 32. 



41 



SIBOGA-EXPEDITIE XXIV' *. '^ 



