•236 
THE VOYAGE OF H.M.S. CHALLENGER. 
the rest. The test cells are fairly large and numerous (PI. XXVI. fig. 12, t.c .) ; triangular 
and stellate forms with very long rays are the most common, but rounded granular 
ones are also present. The bladder cells are not numerous, and they are rather small. 
The mantle is strong and opaque. It contains pigment cells, and the muscle fibres 
are of large size. 
The post-abdomen is much larger than any other part of the body, and it is the most 
prominent feature in sections (PI. XXVI. fig. 12, p.ah.) and in teased preparations of 
the colony. It is an elongated thread-like body of much the same width throughout, 
and quite opaque. At its posterior termination there is a slight knob resembling a 
rudimentary vascular appendage. In sections (PI. XXVI. fig. 1 2, p.a&.) the post-abdomen 
is seen to be divided throughout its entire length by the usual double septum, on each 
side of which lies an opaque cellular mass in which the reproductive elements are formed. 
Amaroucium nigrum, n. sp. (PI. XXXI. figs. 17-19). 
The Colony is irregularly club-shaped. It is attached by a small base from which it 
gradually enlarges to a much wider upper end. It is not compressed laterally. The 
upper end has an obliquely truncated appearance. The surface is uneven. The colour 
is black. 
The length is 1‘6 cm., the greatest breadth is 5 mm., and the greatest thickness is 
4 mm. 
The Ascidiozooids are of moderate size, but are few in number. They are placed 
vertically in the colony, and their anterior ends form small projections on the surface of 
the upper end ; otherwise they are not visible externally. 
The Test is firm and cartilaginous. It is of a very dark grey -brown colour internally, 
and is Ifiack on the surface. It is quite opaque. The test cells are very abundant, and 
are mostly of elongated, fusiform, and branched shapes. They are all very granular, 
and some of them are of large size, and are pigmented. No bladder cells are present. 
The Mantle, is thick and opaque, and the musculature is well developed. The muscle 
bands are mainly longitudinal in direction, and they are rather wide. 
The Branchial Sac is small, and is not well developed. The stigmata are short 
and rounded. 
Locality . — Royal Sound, Kerguelen Island ; depth, 28 fathoms. 
A single specimen of this remarkable looking species was obtained at Royal Sound, 
Kerguelen Island, from a depth of 28 fathoms. It is a small black colony of elongated 
frjrm, tapering from a wide irregularly shaped upper end downwards to a small area of 
attachment at the opposite extremity (PI. XXXI. fig. 17). The lower part, or stalk, is 
irregular and slightly twisted. No common cloacal aperture is visible. The colour on 
