474 
THE VOYAGE OF H.M.S. CHALLEHGEE. 
Ereutho, Malmgren. 
Ereutho herguelensis, n. sp. {PL XXVIIIa. figs, 20, 21). 
Habitat. — Dredged at Station 149 g (off London Kiver, Kerguelen), January 29, 
1874; lat. 48° 50' S., long. 69° 18' E.; depth, 110 fathoms; surface temperature, 40°’2 ; 
sea-bottom, volcanic mud. 
The larger example measures 30 mm. in length, with a diameter at its widest part 
anteriorly of about 3 mm., exclusive of the feet. 
In general configuration this form agrees w'ith Ereutho, Malmgren, having thirteen 
pairs of bristle-tufts. The frilled cephalic lobe had evidently been surmounted by a 
series of grooved tentacles, while interiorly are a number of smooth ones. The dorsum 
anteriorly is very rugose, and the large buccal surface is almost papillose. 
The bristles begin on the buccal segment, and number thirteen pairs. They are borne 
on setigerous processes, which correspond in length to those of the common Zetlandic 
form. The bristles (PI. XXVIIIa. fig. 20) differ from those of the latter species in having 
shorter and less attenuate tips. Both are distinctly serrate, the points being situated 
on rudimentary wings, which are only indicated in certain positions by a double line at 
the edge of the bristle, and most distinctly marked in the Zetlandic form. Below the fifth, 
sixth, and seventh setigerous processes are three greatly expanded glandular areas, some- 
what in the form of suckers. Moreover, each bristle-tuft is ensheathed by an anterior 
and posterior cuticular lamella, which terminates su23eriorl}^ in a distinct papillary process, 
longest anteriorly. Each process is composed of cuticle and hypoderm. 
The hooks (PI. XXVIIIa. fig. 21) somewhat resemble those of Ereutho smitti, 
Malmgren, but they bear three distinct teeth, viz., the great inferior fang, and two above 
it. A well-marked heel exists posteriorly. The ventral outline presents a somewhat 
prominent convexity near the middle. The anterior inferior process is less produced than 
in Polycirrus aurantiacus, as figured by Malmgren. 
The pale greyish mud in the intestine was mainly composed of Diatoms, sponge- 
spicules, and here and there a fragment of a Eadiolarian. 
The hypoderm. in this species is very largely developed on the ventral arch, that is on 
the region below the bristle-bundles. It forms a thick, glandular, and somewhat lax 
investment, and there is no separation of the area outside the nerve-cords as in the 
common British Polycirrus. The dorsal arch of the hypoderm is much thinner. The 
nerve-cords are large and rounded, and have a fibrous sheath externally. The circular 
muscular layer is strong. The longitudinal ventral muscles are somewhat narrow and 
extended, though thicker than the dorsal, which meet in the median line. The oesophagus 
shows externally a thin series of longitudinal fibres, then a firm circular belt and the glan- 
dular lining. The great glands of the anterior third and ova are present in the body-cavity. 
