110 Part III.—Twenty-third Annual Report 
Genus Pseudocaligus, A. Scott (1901). 
Pseudocaligus brevipedis (Bassett-Smith). 
1896. Caligus brevipedis, Bassett-Smith, Ann. and Mag. Nat. 
Hist. (6), vol. xviii., p. 11, pl. iii., fig. 1. 
1901. Pseudocaligus brevipedis, A. Scott, Trans. Liverpool Biol. 
Soc., vol. xv., p. 350, pl. ii., figs. 1-4. 
Habitat.—Found attached to the base of the tongue of a Three-bearded 
Rockling, Onos tricirratus, captured at the mouth of the River Dee, 
Aberdeen, November 23, 1904. Eight specimens of a Bomolochus, 
probably B. onosi, were also found on the same fish adhering to the gills 
and gill-arches. 
Genus Lepeophtheirus, Nordmann (1832). 
Lepeophtheirus sturtonis, Kroyer. PI. v., figs. 7-14. 
1837. Lepeophtheirus stwrionis, Kr., Tidsskrift, i., Tab. vi., fig. 6. 
Description of the female.—The female of this species has a general 
resemblance to that of Caligus diaphanus, Nordmann, but is much larger, 
being fully half an inch in length (about J4mm.). 
The cephalic shield is nearly circular in outline, and the frontal plate, 
which is not very prominent, is without lunule. 
The last thoracic segment is considerably shorter than the cephalic 
shield, and is only slightly longer than broad. 
Abdomen moderately narrow and elongated, being equal to nearly 
three-fourths the length of the last thoracic segment. Furcal joints very 
short (fig. 7). 
The basal joints of the antennules are considerably dilated, and the 
end joints though short are also tolerably stout (fig. 8). 
Antenne robust and armed with a large and strong claw, the distal end 
of which is bent at nearly a right angle, as shown in the drawing (fig. 9). 
The mandibles resemble those of LZ. pectoralis, O. F. Miiller. 
The basal-joint of the second maxillipeds is moderately stout and 
elongate, and armed with a short but strong terminal claw (fig. IL): 
The “ palpi,” though slightly dilated at the base, have the sides nearly 
parallel, and the two branches of the bifid extremity are tolerably 
elongated (fig. 10); the small appendage at the bases of the palpi bear 
each one moderately large spine and two small ones, as shown in the 
drawing. 
Sternal fork very stout and with triangularly divergent branches 
(fig. 12).* 
Fourth pair of thoracic legs stout, each with a single three-jointed branch ; 
the outer distal angle of the first joint in each branch terminates in a 
small tooth, a stout spine springs from the outer distal angle of the 
second joint, while the end joint is armed with three terminal spines of 
varying lengths (fig. 13). 
The short furcal joints bear a few small apical sete or spines (fig. 14). 
Habitat.—Taken from a Sturgeon, Acipenser sturio, Linn., captured 
about 16 miles S.E. by E. of Aberdeen, and landed at the Fish Market, 
Aberdeen, on December 29, 1904. I am indebted to Mr. Bowman, 
Aberdeen, for this: addition to the marine copepod fauna of Scotland. 
* Kroyer in Naturh. Tidsskr. 1 Band (1837), Pl. vi., fig. 66, shows the ends of the 
branches of the sternal fork slightly bifid; but the figure in Naturh. Tidsskr. 3 R., 
2 B. (1863), Pl. xvii., fig. 4, represents the sternal fork of another form bluntly pointed 
at the ends, and with which our figure is identical. 
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