PHOXUS SIMPLEX. 
141 
peduncle is very short ; and the flagellum is scarcely 
longer ; the secondary appendage consists of but three 
articuli, and is nearly as important as the primary, which 
is formed of hut four. The inferior antennae are about 
as long again as the head, and three times as long as the 
superior ; the peduncle does not reach as far as the 
apex of the projecting head ; and the flagellum, which 
consists of about ten or twelve articuli, has each articu- 
lus almost as broad as long. The coxae of the arms and 
first two pairs of walking legs are very large, broad, and 
much deeper than the respective segments of the body ; 
the three anterior are furnished, towards the posterior 
portion of the inferior margin, with four simple hairs, 
which number appears to us to be persistent, as five are 
to P. Holbolli , and a greater number to P. plumosus ; 
the arms are subequal, the first pair being rather the 
smaller ; the wrist is short, and the hand twice as long 
as broad ; the inferior margin runs parallel with the 
superior, but is not quite so long ; the palm is slightly 
oblique, and defined by a small tooth at the inferior 
angle; the finger is of the same length as the palm. 
The second pair of arms vary but little in form from 
the preceding ; the hand is a little larger, it is rather 
broader towards the base, both margins are convex, the 
inferior is about one-third shorter than the superior ; 
the palm is much more oblique than that of the first 
pair, it is also slightly convex, and defined by a larger 
tooth at the inferior angles : the finger is slightly curved, 
and is about the length of the palm. The walking legs 
are rather slender. The first two pairs have the fingers 
rather long and straight. The fourth pair of these legs 
are longer than the third, but the fifth are much shorter 
than either, and apparently useless ; the squamiform 
thigh is larger than that of the preceding legs, and 
