8 ARKIV FÖR ZOOLOGI. BAND 7. N:0 5. 



first few segments are scarcely raised above the general sur- 

 face of the chaetigerous annulus, but those of the tenth and 

 succeeding segments are clearly seen as elongate ridges, extend- 

 ing from just below the notopodinm practically to the mid- 

 ventral line (Fig. 2). for the neuropodia of the right and left 

 sides are there separated from each other by the narrow and 

 shallow mid-ventral groove. ^ The neuropodia are of the elong- 

 ate type, like those of A. marina, and differ from the short 

 neuropodia present in A. daparedii and A. assimilis. 



Nephridiopores are present in all the specimens on seg- 

 ments 5 to 9 inclusive; the pore is immediately dorsal to the 

 upper end of the neuropodium. 



Another external feature associated with the parapodia 

 is Avorthy of note, namely, the presence of a small round or 

 oval depression, about 0,2 5 to 0,5 mm. in diameter, immedia- 

 tely ventral to certain of the notopodia. These depressions 

 are best seen in the type specimen in which they are present, 

 on both right and left sides, in segments 13 to 20 inclusive 

 (Fig. 2). It is interesting to note that the segment bearing 

 the additional notopodium exhibits a depression similar to, but 

 slightly smaller than, that of the preceding normal segments. 

 These pits are also present in two of the Saldanha specimens 

 but on the last two or three chaetigerous segments only. 

 Depressions identical in form and position are occasionally 

 seen in A. cristata but their significance is, as yet, unknown. 

 Sections were made of a piece of the body wall between the 

 eighteenth notopodium and neuropodium of one of the Sal- 

 danha specimens, but the preservation of the tissue is not 

 sufficiently good to permit critical observations on the histo- 

 logy of the cells. The epidermis of the depressed area is 

 composed, almost entirely, of deeply staining, narrow, col- 

 umnar cells. Although the position of the pit reminds one 

 of that of the lateral sense organs (»Seitenorgane») of Capi- 

 tellidae and Scalibregmidae, it is, at present, impossible to 

 say if the structure in question is of this nature. 



Setae. 



The setae in some of the notopodia seem to be in two 

 more or less distinct series, an anterior and a posterior; the 



^ The ventral and nietastoniial grooves are feebly marked in all the 

 specimens. 



