26 



ANNELIDS. I. 



convex edge of the scale (PI. I, fig. 4) are seen under a lens several rounded, not very prominent, 

 papilliform bodies, a part of which is also spread over the surface of the lateral half of the scale 

 within the edge. 



Examined under the microscope each of these bodies proves to be provided with a single little 

 thread-shaped papilla (PI. I, fig. 1), a fact which calls to mind Hannothoe mollis,* described from the 

 Christianiafjord by Sars. However, the respective shape of the named bodies in the two species is 

 rather different; in H. mollis the bodies in mention are rather lengthened, almost cylindrical or conical 

 with rounded apex; in the species from the Iugolf-Expedition they are short, thick, almost dome-shaped 

 or mammiform; some of them are constricted at the base, rendering the shape more ovoid; but each 

 of them carries on the apex the above named filiform papilla, in aspect quite like those which Sars 

 describes and figures in his H. mollis. In other respects there is hardly any resemblance between 

 the two species. 



The proboscis not being protruded I cannot say anything about this organ. 



The foot (fig. 8) is nearly as high as long; its two 



branches taper to a rather pointed apex; each of them is 



provided with a strong acicle. The dorsal cirrus — lacking 



in the parapodium figured — is rather long and tapers in 



a short filament. Near the base of the dorsal cirrus, and 



median to this, is situated a warty prominence resembling 



the elytrophore in those segments where the scales have 



dropped off, but it is not quite as prominent and a little 



more pointed in shape. There are no corresponding 



prominences of that sort in the scale-carrying segments. 



Some few papillae of the usual clavate form are seen on 



the dorsal as well as on the ventral cirrus. The segmental 



papillae are only very little prominent. 



The setae of the notopodial branch (PI. II, figs. 10 — n) are relatively slender; they are feebly 



curved but, for the rest, of the sword-shape usual in the genus of Hannothoe. The dentition along 



the edge is weak, and in most of these setae is seen towards the apex a dilatation not very prominent. 



(PI. II, fig. 10). 



The ueuropodial setae (PI. I, figs. 2, 3, 5) are very characteristic; the shaft is rather long and 

 thick, the endblade broad and relatively more sharply limited against the shaft than usual; the former 

 tapers gradually towards the apex, which is long and strongly curved and with a single tip. The 

 dentition of the endblade is conspicuous on the concave edge, where a row of rather strong spines is 

 seen. In some of these bristles small acute spines are scattered over a part of the endblade (PI. I, fig. 5). 

 At the first examination of this form I judged it to be the species from the Challenger-Ex- 

 pedition, described by Mc. In tosh under the name of //. opalusa, which has been captured near 

 Juan Fernandez and Valparaiso; it seems to me beyond doubt that the two forms are closely 

 related, especially the form and aspect of the setae seem to agree completely. As the author, however, 

 docs not at all mention papillated bodies on the scales which I have described above, and as I do not 



fig. 8. 



