REPORT ON THE ANNELIDA. 
405 
than in Praxilla herguelensis) have largely developed spines. The next segment has no 
distinct whitish band, but the next four have. It is uncertain whether the first has 
lost its band, but both specimens are in the same condition. 
The hooks approach the type of Praxilla assimilis, the crown being comparatively 
flat and broad (PI. XXXVa. fig. 8), with upwards of six teeth above the great fang. The 
outline of the shoulder differs, both from the form mentioned and Praxilla herguelensis, 
since the anterior is much less than the j)osterior projection, a feature, however, on which 
much reliance cannot be placed. The vibrissse arise a very little below the great fang. 
The inferior region of the hook is comparatively short. 
The somewhat coarse sand in the intestine contained a considerable number of 
Diatoms, besides sponge-spicules, and a few Foraminifera and Gregarinse. 
The hypoderm in this species is somewhat firmer than in Praxilla prcBtermissa, so 
that the tissue in section is less cellular, and retains its outline better. The nerve-area 
in each is similar, and the same may be stated in regard to the circular muscular coat. 
The longitudinal dorsal muscles in the new species present an evident distinction, for they 
are connate for a considerable distance in the median line. The longitudinal ventral are 
more compact and massive. In the intervals between the bristle-tufts a thin band of 
muscular fasciculi occurs between the dorsal and ventral longitudinal muscles, and below 
the upper attachment of the oblique. 
Praxilla herguelensis, n. sp. (PI. XL VI. fig. 7 ; PI. XX Va. fig. 6). 
Habitat. — Dredged at Station 149g (off London Piver, Kerguelen Island), January 
29, 1874 ; lat. 48° 50' S., long. 69° 18' E., in 110 fathoms ; surface temperature, 40°'2 ; 
sea-bottom, volcanic mud. 
None of the specimens are perfect, but it seems to be a species of some size, reach- 
ing a diameter of 2 '8 mm. 
The cephalic plate considerably differs from that of Praxilla prcetermissa, having a 
much more expanded margin, with a notch (in lateral views) at the commencement of 
the upper (or posterior) third. The margin then becomes a little narrower toward the 
median dorsal notch, which is somewhat shallow. Anteriorly (ventraUy) the central 
conical process is well marked, and it has a pit at the base posteriorly, where it abuts 
on the central ridge of the flat cephalic plate. The ridge stretches from the conical 
process almost to the dorsal margin of the plate, is acute, and clearly defined by a deep 
groove on each side. The posterior part of the ventral median process is comparatively 
isolated, so that it looks like a disk appended to the boldly defined median ridge. The 
proboscis is studded with proportionally large and distinct papilljB of a slightly conical 
or globular shape. 
