ee) 
‘ys 
’ 
of the Fishery Board for Scotland. 199 
slender and two-jointed—both branches strongly setiferous. The maxille 
are very similar to those of the Calanide (fig. 5). Anterior foot-jaws 
furnished with several marginal setiferous processes; the Jast process 
armed with a strong spine in addition to three aculeate sete ; terminal 
joints small, furnished with a number of slender sete. Posterior foot- 
jaws somewhat rudimentary, bearing numerous marginal and delicate 
plumose sete. A long delicately plumuse hair springs from the lateral 
aspect and near the base of the foot-jaw, and a few similar hairs from 
near the middle and distal extremity (fig. 7), The first pair of swimming 
feet are comparatively short ; both branches are of about equal iength, 
and composed of three sub-equal joints. The second joint of the outer 
branch bears a long, curved, spiniform, and blunt-pointed marginal seta. 
The last joint is armed with three spiniform marginal sete, but these are 
considerably shorter than that on the second joint ; both branches other- 
wise more or less setiferous. The second pair of swimming feet have the 
inner branches greatly elongated—being equal to about three times the 
leneth of the outer branches (the third joint alone is nearly equal to twice 
the length of the outer branch). The end of the outer branch extends to 
a little beyond the second joint of the inner one. The long joint of the 
inner branch is armed on the outer aspect and near the middle—but 
nearer the proximal than the distal end—with a large aculeate spine, and 
with two similar but smaller spines on the inner aspect—one near the 
middle of the joint, but posterior to the large outer spine, and one about 
one-fourth of the length of the joint from the distal end. This joint is also 
furnished with three stout and moderately long terminal spines. Both 
branches of the third and fourth pairs of feet are nearly equal and similar to 
each other, except that the fourth is a little smaller (figs. 10, 11). Fifth pair 
small, basal joint scarcely developed, produced exteriorly into an elongate 
digitiform process, bearing a single apical seta, and furnished interiorly 
with a very long and curved aculeate seta, the proximal part of which is 
stout. The secondary branch (or joint) is foliaceous, spathulate in form, 
the greatest breadth being rather less than half the length ; the inner margin 
nearly straight, bearing several minute teeth; outer margin and end 
sinuate and provided with a number of sete, the innermost being 
nearly three times the length of the joint from which it springs (fig. 12). 
The postero-lateral angles of the first abdominal segment are produced 
into tooth-like processes. The postero-lateral angles of all the thoracic 
and abdominal segments are acutely angular—the last abdominal segment 
is very short—with the dorsal part of the posterior margin spiniferous, 
the central spine being large and prominent, the others small. Caudal 
stylets short ; the longest of the caudal sete are scarcely equal to twice 
the length of the abdomen and caudal stylets combined. One ovisac. 
No males of this form have yet been observed in the Firth of Forth, 
but females are frequent. 
This appears to be the form described in the monograph of the British 
Copepoda as the ‘male’ of Longipedia coronata. It also closely agrees 
with the description and figures of Claus, both as regards its size and 
structural details, with the exception of the arrangement of the spines on 
the long joint of the inner branches of the second pair of swimming feet. 
Claus’s figure agrees with that of Giesbrecht in this respect. But the 
form now described does not agree with that described by Giesbrecht in 
size, in the form of the second and fifth pairs of thoracic feet, and in some 
other important points. ‘That described by Giesbrecht, on the other hand, 
agrees perfectly with a form recently discovered by my son, Andrew Scott, 
while examining some dredged material from the Firth of Forth, and 
which is provisionally described as Longipedia coronata,.var. minor. The 
following is a description of this variety :— 
