Male of Alebion echinatus — Shiino 
179 
TABLE 1. 
Details of Armature on Legs of Alebion echinatus Capart 
LEG 
BORDER 
STERNAL 
PLATE 
PROTOPODITE 
EXOPODITE 
ENDOPODITE 
I 
II 
III 
I 
11 
III 
I 
outer 
inner 
IP 
C 
1H, 1 H 
3P, 2p 
c 
3P 
II 
outer 
inner 
f 
f, Ip 
IP, f 
f, 1H 
c, IP 
1 H 
c, IP 
1 H 
c, 6P 
C 
IP 
c 
c, 2P 
6P 
Ill 
outer 
inner 
f 
f, lh, 5h 
IP, f 
1H 
c, IP 
c, 1 H 
c, IP 
c, 2 H, lh 
5P 
c 
c 
c, 2P 
4P 
IV 
outer 
inner 
2p, lh 
Abbreviations: c, row of hairs; f, membraneous flange; H, longer spine; h, shorter spine; H, modified spine peculiar to 
the genus; P, longer plumose spine; p, shorter plumose spine. Roman numerals indicate the numerical orders of the legs or of 
the joints and Arabic the number of spines or other armature present on each. 
stouter spines, one on each side of midline. 
A pair of horn-like spermatophores are at- 
tached on the ventral surface close to pos- 
terior end, with their apices directing forwards 
and diverging. Abdomen two-segmented, 
small, not surpassing the middle of diagonal 
processes of the preceding segment. First seg- 
ment is narrowly inserted into median sinus 
of preceding segment then widens posteriorly, 
bearing a pair of small oboval, dorsal plates, 
which are parallel and separated from each 
other by a deep, wide, median sinus. Ventral 
surface has inconspicuous, symmetrically ar- 
ranged tubercles. Second segment is cordi- 
form and covered from above by dorsal plates 
of the first, beyond which it does not extend. 
First antennae with apical joint short, ter- 
minating in a swollen, spinulate knob; basal 
joint obovate and fringed on anterior border 
by short, conical, thickly ciliated spines as 
well as by a few setae. Claw of 2nd antennae 
tapering towards curved blunt apex and with- 
out accessory spinule, middle joint conical, 
and basal one short, broad, with an oval boss 
on the outside. Mouth tube elongate conical. 
First maxillae replaced by small, insignificant 
oval bosses. Second maxillae triangular, placed 
outside the base of mouth tube. Apical joint 
of 1st maxillipeds traversed near the tip by a 
diagonal row of spinules and terminating in 
two unequal flagella, both edged with fine 
pectination. Second maxillipeds have nearly 
fusiform palm and powerful finger ending in 
bifurcate tip and carrying a short plumose 
spinule on inner border. Sternal furca absent. 
First three pairs of legs biramous, with both 
rami two-jointed in first pair, three-jointed in 
other two. Endopodite of first legs half as 
long as exopodite, first joint of both rami 
proportionally much longer than second. Two 
apical joints of exopodite of second legs 
short. Distal joint of endopodite of second 
legs narrow. Exopodite of third legs shorter 
and narrower than endopodite, apical joint 
of latter much reduced. Fourth legs are minute 
papilliform stumps without any distinct arti- 
culation. Arrangement of spines and other 
armature of legs is given in Table 1. 
Exopodites of first three legs armed with 
falciform spines, peculiar to the genus, their 
distribution on the legs is shown in Table 1. 
Two spinules on inner margin of apical exo- 
podite joint of first legs edged with a few 
cirri only. Basal apron combining third legs 
has two triangular, raised areas on posterior 
face on each side, outer one of these with a 
