of the Fishery Board for Scotland. 217 
This form—Zogagus latus—has a close general resemblance to 
— Caligus, except that the frontal plates are without Junulew. The cephalic 
shield is sub-rotundate, being nearly as broad as it is long, and it is also 
nearly equal to two-thirds of the entire length of the animal. The fourth and 
fifth thoracic segments are short but of moderate width ; the last is about 
twice the length of the preceding segment and is sub-quadrate in outline. 
The urosome is small and appears to be composed of two segments. The 
furcal joints are also short and broad, while the apical sete have the 
appearance of small lamelliform plates fringed with delicate hairs (fig. 1). 
The antennules are moderately stout, and the first joint is furnished 
with a number of short and stout plumose bristles round the distal end, 
but the second joint is smaller and bears a few apical spines (fig. 2). 
The second antennules are also stout, and they are each armed with a 
strong terminal claw (fig. 3). 
The first pair of maxillipeds are considerably elongated and resemble 
nearly the same appendages in Vogagus borealis, Stn. and Ltk. (fig. 4). 
The second maxillipeds are short and very robust, their distal end is 
moderately truncate, and they are each armed with a short but strong 
terminal claw (fig. 5). 
The first pair of thoracic feet have both branches short, sub-equal, and 
two-jointed ; each branch is provided with three stout and moderately 
elongated terminal set, the outer branch having also a few short spines 
on the exterior margin, as shown in the drawing (fig. 6). 
The second pair is rather more robust than the first, both branches 
being two-jointed and of nearly equal length. The first joint of the inner 
branch has one plumose seta on the inner margin, while the second bears 
seven or eight similar setz round its distal end. The first joint of the 
outer branch is also furnished with a seta on the inner margin anda 
small spine on the outer distal angle, but the end joint carries five sete 
round the inner margin and apex and four spines on the exterior edge 
fig. 7). 
a third pair, which, like the first and second, has both branches 
bi-articulated, is also moderately stout, but the branches, though armed 
nearly as in the second pair, are rather shorter (fig. 8). 
The structure of the fourth pair is similar to that of the other three, 
but this pair is rather smaller, and both branches are very short. One 
seta springs from the inner distal angle of the first joint of the inner 
branch, while the second joint carries three or four round the distal end. 
The first joint of the outer branch is provided with a small spine 
exteriorly, while the end joint has five sete round the inner margin and 
apex, and three or four small spines on the outer margin (fig. 9). 
Habitat—On piked dog-fish (Squalus acanthius) captured in the 
North Sea in 1992. 
Nogagus ambiguus, sp.n. Pl. xv., figs. 10-17 (¢) 
In this species the cephalic shield is of an oval outline, and the lateral 
margins where they meet anteriorly form a more or less distinctly angular 
instead of a broadly rounded front, as in the form just described. The 
last two thoracic segments are of nearly equal size, and their width is 
about one-third of that of the cephalic shield at its widest part. The 
urosome (abdomen) consists of one small segment, and the furcal joints, 
which are also very short, are each furnished with moderately long 
plumose sete (fig. 10). 
The antennules, which are of average size, are also adorned with long 
plumose setz (fig. 11). 
