109 Part I1I.—Twenty-third Annual Report 
Fam. CALicip@. 
Genus Caligus, O. F. Miiller (1785). 
* Caligus abbreviatus, Kroyer. PI. v., figs. 1-6. 
1863.  Caligus abbreviatus, Kr., Bidrag til Kundskab om 
Synltekrebsene; Naturh. Tidsskr., 2R., 2B., p. 61, pl. in, 
fig. 3, a—k. 
Description of the Female.—The Female represented by the drawing, 
(fig. 1) measures 5mm. (4 of an inch). The cephalic shield is nearly 
circular in outline, but is rather widest behind the middle; the width of 
the frontal plate is scarcely half the width of the cephalic shield at the 
widest part; lunule very clearly defined. Abdomen and furcal joints 
very short, as represented in the drawing. 
The antennules have the basal joints robust and broadly sub-triangular, 
but the end joints are long and narrow (fig. 3). 
The second maxillipeds are robust, and form powerful grasping organs 
(fig. 5). 
a sternal fork, which is moderately stout, and the branches of which 
are not greatly divergent, has a resemblance to the same appendage in 
Lepeophtheirus Thompsont, Baird (fig. 4). 
The fourth pair of thoracic legs are elongated; the basal joint is 
moderately stout and one-branched ; this branch is slender and composed 
of two joints, and the end-joint is about twice the length of the first, and 
is armed with a long, slender and claw-like terminal spine and a short 
spine near the distal end of the outer margin; the first joint is also 
furnished with a spine on the outer distal angle (fig. 6). 
Habitat.—-On a Ballan Wrass, Labrus bergyléa, captured in the Moray 
Firth in October 1904, and on another fish of the same species captured 
in the North Sea. Krdyer also obtained his specimens of the Caligus on 
the Ballan Wrass. 
A young specimen representing the Chalimus stage of this Caligus is 
represented by figure 2, and was obtained along with the adult form. In 
this specimen the siphon is still present, showing a somewhat dilated 
and biarticalated base ; the antennules are composed of two short subequal 
joints, the cephalic shield is elongate-ovate in outline, and the abdomen 
is very short. The frontal plate slopes posteriorly, and the development 
of the lunulz is considerably advanced. 
Caligus minimus, A. W. Otto. 
1828. Caligus minimus, Otto, Nova Acta Acad. Ces. Leop., 
vol. xiv., p. 354, pl. xxii., fig. 7. | 
1840. Caligus minutus, M. Edw., Hist. Nat. Crust., vol. iii., 
p. 450. 
1901. Caligus minimus, A. Scott, Trans. Liverpool Biol. Soc., 
vol. xv., p. 349, pl. 1, figs. 1-8. 
Habitat.—On a Bass, Labrax lupus, captured above Queensferry on 
February 4, 1903. This appears to be the first record of C. minimus 
for the Forth district. 
* This species closely resembles, and is probably identical with, Caligus centrodonty 
Baird. (Cf. Brit. Entom., p. 272-3, Tab, xxxii., figs. 6, 7.) 
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