REPOET OR THE ARRELIDA. 
79 
The body is on the whole pale ; a faint greyish tinge, however, occurs along the 
middle of the dorsum and on the scales, and a little brownish j^igment on the folds of 
the mouth anteriorly. 
The head is distinguished from Lagisca propinqiia, Mgrn, Lagisca jeffreysii, MT., 
and Lagisca rarispina, Sars, by the much larger size of the eyes ; indeed, it resembles 
Evarne in this respect, though the basal portion of the tentacle is much diminished, 
and the points of the head on each side less conspicuous ; and while the posterior 
pair of eyes are nearer each other, the trapezoid formed by the eyes is smaller than in 
any of the foregoing. The tentacle has a proportionally slender base, and in the 
specimen (which probably is imperfectly developed) the distal region is short, and rapidly 
terminates in a filiform extremity. It has a somewhat sparse series of clavate papillae. 
The antennae are short and filiform. The tentacular cirri agree with the tentacle. The 
palpi are comparatively long and pointed, and show peculiar bifid papillae. 
The first scale is more or less rounded, and studded with somewhat large papillae, a 
conspicuous row considerably exceeding the others in size occurring along the posterior 
border. The shape of the succeeding scales alters to the elongate type in the usual 
manner, and their free surface is covered with large papillae, the posterior row being 
visible under a lens. A few long cilia also occur on the latter border (PI. XYIII. 
fig. 7). 
Both the dorsal and ventral bristles are pale. The former (PL VIIa. fig. 5, rejjre-" 
senting an intermediate example) are characterised by remarkably close rows of spikes. 
The longer forms (PI. VIIa. fig. 6) have more attenuate extremities. 
The ventral bristles consist superiorly of a series (PI. VIIa. figs. 7, 8) with 
distinctly alternate rows of spikes, the bifid portion at the tip in some being imperfectly 
seen from its minuteness. The rows of spikes are boldly marked and long. Toward the 
middle of the series the peculiar character of the bifid tip (PI. VIIa. fig. 9) is evident, 
and its distinction from that in any of the known forms is clearly demonstrated. All 
the bristles are very translucent and delicate. 
The size and arrangement of the eyes, the minute structure of the scales, and the 
structure of the bristles, are characteristic. Thus, in comparison with Lagisca progiinqua, 
Mgrn., to which perhaps it comes nearest in regard to the scales, it diverges much in 
the structure of the tips of the ventral bristles and in the arrangement and size of the 
eyes. 
Grube has a Polynoe tenuisetis ^ from Rio Janeiro, but the pellucid smooth scales 
distinguish it from the foregoing. The Polynoe zonata of Langerhans,^ from Madeira, 
approaches the form described above in the structure of the head and its appendages, 
and in the size of the eyes, but it deviates considerably in the structure of the bristles, 
which resemble those of Lagisca propinqiia rather than the present species. 
1 Annulata CErstediana, p. 20. 
2 Zeitschr.f. iviss. Zool, Bd. xxxii. p. 275, Taf. xiv. fig. 5. 
