370 
THE VOYAGE OF H.M.S. CHALLENGER. 
connected by a duct (? vessel) with tlie buccal region. The vessel bifurcates just 
behind the latter region, the right branch joining a cylindrical firm glandular organ 
closely applied to the gullet, the left passing round the latter toward the dorsal region. 
The cylindrical glandular organ formerly mentioned is joined a little in front of its 
posterior border by another U-shaped glandular body of much larger size, but apparently 
of the same structure. One leg of the U is fixed to the former organ, the other is 
attached to the oesophagus. 
The united nerve-cords lie between the ventral longitudinal muscles, and are internal, 
that is, they are bathed by the perivisceral fluid. The ganglia and their lateral branches 
are well marked, and are situated nearly opposite the bristle-bundles. 
The body-wall is composed of a hyaline, slightly areolar, cuticular coat of great 
thickness (PI. XXXVIIa. fig. 1), to the external surface of which the long slender papillae 
are attached. The best developed of these organs are from eight to ten times longer than 
the whole thickness of the body-wall, and each papilla only diminishes very slightly 
toward the tip. The whole surface, as already mentioned, however, is obscured with fine 
Diatom ooze, which also binds several adjacent papillae into a mass. A hypodermic 
process passes through the translucent cuticle at the base and goes almost to the extremity 
of the papilla. The basal part of this hypodermic axis is dilated at its origin. The 
hypoderm is comparatively thin, and the same may be said of the circular muscular coat. 
A nearly continuous layer of longitudinal fibres (homologous with the dorsal longitudinal 
muscles) envelops the body-wall within the former, and gives a glistening aspect to the 
inner surface. The two ventral longitudinal muscles form narrow flattened ribbands on 
each side of the nerve-cord. 
In several respects, such as the great size, the condition of the skin, the paucity of 
the branchiae, and the internal anatomy, this form presents diagnostic features. The 
Stylarioides parmatus of Grube,^ from the Philippines, somewhat resembles it in outline, 
but diverges much in regard to the branchiae and the nature of the ventral bristles. The 
anatomy of this Philippine Annelid is not given. 
Brada, Stimpson. 
Brada mammillata, Grube (PL XLIII. fig. 11 ; PL XXIIIa. figs. 7, 8). 
Brada mammillata, Grube, Jabrb. d. Scbles. GeseUsch. fiir 1876, Bericbt d. Naturwiss. sep.) 
Abd.), p. 40. 
Habitat. — Dredged somewhat plentifully at various points off Kerguelen, e.g., 
Station 149 (Accessible Bay), January 9, 1874 ; lat 49° 8' S., long. 70° 12' E. ; depth, 20 
fathoms; sea-bottom, volcanic mud. Station 149 a (Betsy Cove), January 14, 1874; 
lat. 49° 8' S., long. 70° 9' E.; depth, 40 fathoms; sea-bottom, volcanic mud. 
1 Annelid enfauna d. Philippinen, p. 199, Taf. xi. fig. 1. 
