PHOXUS PLUMOSIJS. 
147 
superior antennae have the peduncle reaching as far as 
the extremity of the head; the first joint is very long, 
and reaches nearly to the anterior margin of the head, 
* — it is furnished upon the inferior margin with three 
short plumose hairs; the second joint is very short, 
being but little longer than broad, inferiorly slightly 
dilated, and armed with five simple hairs ; the third joint 
is shorter than the second, and more slender ; the fla- 
gellum is slender, and as long as the peduncle, consisting 
of seven or eight articuli, of which the first is as long 
as three others; the secondary appendage is slender, 
and nearly as long as the primary, and consists of six 
articuli. The inferior antennae are rather shorter than 
the superior ; the peduncle reaches as far as the ex- 
tremity of the first joint of the peduncle of the su- 
perior ; the penultimate joint is the longest, and is 
inferiorly dilated into a squamiform process, with a 
convex margin, and fringed with several plumose hairs, 
as is also the antero-superior margin ; the last joint is 
short and slender ; the flagellum is more slender still, — ■ 
it is shorter than the peduncle, and consists of seven or 
eight articuli, of which the first is as long as the two 
succeeding. The mandibles are short, (having the in- 
cisive margin armed with denticles,) and furnished with 
a long two-jointed appendage ; the distal joint being 
longer than the basal, terminating obliquely and carry- 
ing a row of closely-set hairs, which increase in length 
towards the extremity. The foot-jaw bears a consi- 
derable resemblance to an ordinary leg, but is distin- 
guishable by a small squamiform process, developed 
both from the third and fourth joints, which are sub- 
equally short ; the fifth is long, and fringed upon the 
inner margin with hairs ; the sixth joint is scarcely half 
as long as the fifth, fringed like the preceding, the fringe 
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