EEPOET ON THE ANNELIDA. 
05 
third of the body, stretches over about seven successive feet, and thus its length 
is a marked feature. The setigerous dorsal lobe of the foot is feebly developed, and 
projects so slightly that the tips of its bristles pass little beyond the bases of the 
ventral bristles. The dorsal bristles are translucent and somewhat slender, having fine 
serrations along the edge, and a peculiar tip (PI. XIIa. fig. 14, one of the shorter dorsal 
forms) which gives an indication of the bifid condition present in the ventral series. 
The ventral is the chief setigerous lobe, and forms a well-marked cone in an antero- 
posterior view. The bristles are also translucent and somewhat slender, and the tips are 
distinctly bifid. The serrated region is long in the superior bristles (PI. XIIa. fig. 15), 
and shorter and broader in the inferior (fig. 16). The terminal hook is strongly curved, 
while the secondary process beneath stands outward at a wide angle to the long axis of 
the bristle. 
The larger example is a female, and probably only the pair existed in the sponge. 
The translucency of both this commensalistic form and the Syllis is noteworthy. The 
specimen is not in a good state for minute examination, but in transverse section the 
typical structure exists. The ventral area is almost wholly occupied by the large 
rounded nerve-cords. The comparatively large ova are grouped chiefly at the bases of 
the feet. 
Harmothoe, Kinberg. 
Harmoihoe henthaliana, n. sp. (PI. XIII. fig. 3 ; PI. XX. fig. 7 ; PI. Xa. figs. 9, 10). 
Habitat. — Two specimens were dredged off the American coast at Station 45, 
May 3, 1873 ; lat. 38° 34' N., long. 72° 10' W. ; depth, 1240 fathoms ; bottom tempera- 
ture 37°'2, surface temperature 49°'5 ; blue mud. It was accompanied by several 
peculiar types in other divisions of the invertebrates. 
The head (PL XIII. fig. 3) is pale and appears to be devoid of eyes, but in the 
larger specimen four very minute eyes are present ; the posterior situated within the 
posterior border and at the outer corner, the anterior, on the lateral eminence about the 
middle of the head. There is thus no possibility of confounding this form with 
Harmothoe imhricata, the eyes in which, besides, are very much larger. The tentacle 
is a simple tapering process, somewhat shorter than the palpi, and the tentacular and 
long dorsal cirri have a similar shape with very attenuate extremities. All these have 
clavate cdia. The palpi are rather long and gently tapered, as well as apparently smooth. 
The ventral cirrus is glabrous and proportionally large and long, the tip reaching the 
extremity of the elongated inferior lobe. The scales are pellucid and pale (PI. XX. 
fig. 7), a few long and somewhat conical papillse being visible at the posterior border. 
