.—_ 
——y; 
Pee eee 
Description of a Species of Caligus. 235 — 
oblique position. 'This maf be considered an appendage to the 
maxilliped just described. It is similar in the two sexes. 
The second pair of maxillipeds are rudimentary. They are 
Situated along side of the buccal mass. The basal joint is a large 
fleshy mass, having a strong spine directed backward on its poste- 
rior side, (fig. 4, a.) Upon this mass near its anterior part, there 
is a very short cylindrical leg, of a single joint, which bears at its 
apex a long slender spine, and three or four small seta. It moves 
in every direction, and the spine is as frequently nee inward 
or backward, as in the manner given in the figure 
The legs of the third pair are situated each on a fleshy base, 
just exterior to the spine of the preceding pair. ‘They are long 
and slender, and composed of three joints. The basal joint is 
rather longer than the two terminal joints of the first pair, and 
diminishes very gradually to its apex. The second joint is one 
third longer than the basal, and about one fourth as large, and is 
of uniform size throughout. At its apex, below, it has a slender 
ensiform extension, which is doubly edged with a finely pectina- 
ted membrane, (fig. 4, b.) The terminal joint, is very similar to 
the process just described, but is much longer. A single short 
spine is situated on the second joint, a short distance from the ar- 
ticulation of the terminal joint. 
The fourth pair, the last of those on the cephalic segment, is 
very dissimilar in the two sexes. In the male (fig. 1,) it consists 
of a very large basal joint, articulated at its extremity with astout 
terminal claw, which curves inward and is usually brought in con- 
tact with a strong spine near the apex of the basal joint. The 
breadth of the basal joint is nearly one half its length, except at its 
insertion, where it is quite small. Between the strong spine just 
noticed, and the apex of this joint, there is a small fleshy promin- 
ence, and a stout spine. ‘The terminal claw has a small seta near 
its apex. 
In the female, (figs. 18 and 18b,) the greatest breadth of the 
basal joint is scarcely one fourth its length, and it is destitute of 
the strong spine, near the apex; in some young females we see 
traces of it, and the leg has more bulky proportions than here 
stated. The terminal joint is much longer and larger, and more 
fleshy than in the male; it has a short spine at its apex, and three 
or four short sete. 
The remaining pairs of legs are four in number; three pertain 
to the anterior thoracic segment and one to the posterior. 
