EEPOET ON THE ANNELIDA. 
47 
and as the recurved spikes are only seen on one side in relief, it is probable that they do 
not entirely surround the bristle. The shaft likewise shows numerous chitinous prickles. 
Viewed as a whole, the bristle is somewhat fusiform, narrow at tip and base, and dilated 
in the middle. 
The ventral bristles (PI. Va. fig, 2) have a brownish colour. The shaft slightly 
dilates upward toward the spur, from which it diminishes to the tip. The latter is 
strongly hooked, and the inward curve of the dorsal edge of the region below is much 
more pronounced than in Lcetmonice producta, var. ivyvillei. The setae or pinnae of the 
tip gradually increase in length from base to apex, the lowest series being shorter and 
stouter than in the last-mentioned variety ; but the spur is similar. 
The arrangement of the cirri seems to be the same as in the two previous forms. 
The two cirri on the first foot are shorter than the succeeding, but all are very delicate 
and tapering, much more so than in either of the foregoing. Nothing is more diagnostic 
than the condition of the ventral cirrus, which forms a very minute filiform process about 
the middle of the greatly elongated foot. It can barely be detected with the naked eye. 
The anus forms a prominent button projecting upward in the middle line at the 
posterior extremity. It is covered by the last pair of scales. In a specimen from Station 
147 the intestine was loaded with greyish mud composed of sponge-spicules, Eadiolarians, 
Foraminifera, Diatoms, &c. 
The specimen from Station 157 has eighteen pairs of scales, but so far as can be 
noticed the great dorsal bristles nearly agree with the description, while the ventral 
mainly differ in regard to the greater number of short stiff ones near the lower edge. There 
are slight differences in regard to the head. Those from Station 244 are much softened 
and injured. The great spines of the dorsum generally show three recurved fangs on one 
side and four on the other, and the shaft is covered with prickles. The largest example 
has a parasitic hydrozoon growing under the scales on its dorsum, with a soft coenosarc 
and peculiar saccate hydranths, which Prof. Allman finds is a new type. The ventral 
bristles of these deep-sea forms are hollow, and become quite flattened by desiccation. 
The extraordinary quantity of Diatoms, stalked Infusoria, spicules of sponges, and 
Synaptce entangled in the mucus amongst the bristles is a striking feature. 
In this form the nerve-cords seem to be much diminished, only a slight thickening in 
the central region of the long area marking their situation in transverse section. 
Lcetmonice producta, var. ivillemoesi (PI. VI. fig. 3 ; PI. Ya. figs. 3, 4), 
Habitat. — This form has a very wide range, extending from the Azores to the 
Antarctic Ocean and the north-eastern shores of Australia and New Zealand. It was 
obtained in the trawl at the following localities, every one of which had a sea-botrom of 
Globigerina ooze : — Station 70 (to the west of the Azores), June 26, 1873 ; lat. 38° 25' N., 
