1886.] DURING THE VOYAGE OF H.M.S, ‘CHALLENGER.’ 103 
single elongated claw ; the antennule has a four-jointed peduncle 
and a long multiarticulate flagellum ; the uropoda are defective but 
evidently are of considerable size, judging from the socket of articu- 
lation. The whole body is covered with short slender spines of 
varying size, but nowhere very long. 
1, ACANTHOMUNNA PROTEUS, 0. sp. 
This species, the only one referable to the genus, is represented 
by two individuals, both males, dredged off New Zealand in 700 and 
1000 fathoms respectively. The larger specimen measures 7 millim. 
in length. ‘The general shape of the body is as in Munna, but differs 
in being covered with innumerable spines, many of which are 
branched ; the spines are nowhere of very great length. The head 
is furnished with a pair of eyes situated laterally ; these are elevated 
upon short stalks ; the abdominal shield is preceded by a short tree 
abdominal segment; it is extremely convex anteriorly, and the 
point of articulation of the uropoda is upon the dorsal surface, 
though near to the lateral margin; behind the articulation of their 
appendages, the abdominal shield is flattened and terminates in 
a truncated, slightly concave extremity. The antennules have a 
four-jointed peduncle, the third joint being the longest, and a 
multiarticulate flagellum longer than the peduncle. The mandibles 
havea palp. ‘The first pair of thoracic appendages are shorter than 
the rest and subcheliform; the remaining thoracic appendages are 
very long, owing to the elongation of the fourth and fifth joints; they 
terminate in a single claw ; these appendages are covered with slender 
unbranched spines, which arise from tubercles. The uropoda are 
defective, but appear to have been larger than those of Munna, &c., 
and possibly more fully developed. 
Station 168; 1100 fathoms. Station 169; 700 fathoms. 
Fam. ASELLID &, 
Genus STeNETRIUM, Haswell. 
1, STENETRIUM HASWELLI, 0. sp. 
A single species of this genus, the only known deep-water species, 
was dredged off the coast of S. America in 600 fathoms. ‘The 
specimen is a male, and measures 16 millim. in length. 
The diameter of the body is everywhere much the same except the 
head and the terminal region of the abdominal shield. The head is 
prolonged into a short rostrum; eyes are present of narrow linear shape, 
and set obliquely. ‘The thoracic segments are subequal in length as 
well as breadth, and the dorsal surface is quite smooth ; the margins 
of the first thoracic segment are prolonged into a triangular spiny 
process ; in the second segment the margin is furnished with a 
smaller spine-like process; in the two following segments there is 
in addition a smaller posterior spine; in the fifth segment the 
antero-lateral spine is much wider, occupying nearly the whole of 
the lateral margin; in the two remaining segments, the lateral 
