238 Part H1.—Twelfih Annual Report 
outwards, bears two distinct one-jointed branches on the exterior margin 
(fig. 14). Anterior foot-jaws four-jointed, with the basal joint very large 
comparatively, and the end joints small; the second joint is produced 
interiorly so as to form a base fora stout curved spine (fig. 15). Posterior 
foot-jaws elongate, seven-jointed, the last five joints small, their entire 
length being very little greater than the length of the second joint (fig. 
16). Swimming-feet robust, both branches three-jointed. The marginal 
spines of the outer branches of the first pair are large and dagger-shaped, 
and project at, or nearly at, a right angle to the outer margin. Those of 
the fourth pair are much smaller, but the marginal sete on both the 
outer and inner branches, but especially on the inner branches, are stouter 
than the marginal sete of the first pair. In the first pair, also, a stout 
spine springs from the inner distal margin of the second basal joint, and 
projects downwards beyond the end of the second joint of the inner 
branches (fig. 17). Fifth pair stout, each consisting of a single three- 
jointed branch. The breadth of the first two joints is greater than the 
length ; while the third joint is longer than broad, being equal to the 
entire length of the first two. The first joint bears a moderately long 
plumose seta on the outer distal angle. The second joint bears a similar 
seta on the inner distal angle, while the last joint bears two plumose setz 
on the inner margin, and one plumose seta and a dagger-shaped spine at 
the apex (fig. 19). Caudal stylets elongate, being equal to the combined 
length of the last two segments of the abdomen ; and, in addition to the 
terminal setze, each of the stylets bears one small hair near the proximal 
end, and another near the distal end of the outer margin. In the male 
the anterior antenne are sixteen-jointed, the last six being more or less 
modified for grasping ; the eleventh joint is comparatively robust and 
hinged to the preceding one. There is also a hinged articulation between 
the penultimate and ante-penultimate joints (fig. 11). 
Halitat.—Off St Monans. Rather rare. 
Remarks.—The species now described differs in some important points 
from any other Cyclopina recorded from the British seas. It resembles 
Cyclopina littoralis in the form of the fifth pair of thoracic feet, but the 
proportional lengths of the joints of the anterior and posterior antenne, 
and the structure of the first pair of swimming-feet, are decidedly different. 
It also, in this respect, differs from Cyclopina ovalis, Brady ; while the 
shorter and much fewer jointed anterior antenne of Cyclopina gracilis, 
Claus, readily distinguish that species from the one now described. 
Genus Pterinopsyllus, Brady (1880). 
Pterinopsyllus insignis, Brady. 
1878. Lophophorus insignis, Brady (8), vol. i. p.° 122; pl xin 
figs. 1-10; pl. xv. fig. 10. 
1880. Pterinopsyllus imsignis, Brady (8), vol. iii. p. 23. (Lopho- 
phorus being preoccupied, Dr Brady substituted the word 
Pterinopsyllus for this genus). 
1893. Pterinopsyllus insignis, T. and A. Scott (32), p. 243. 
Habitat.—West of Queensferry. Frequent. This beautiful species has 
several times been obtained in the part of the Forth estuary referred to. 
In this part of the Forth there are periodic and very marked variations 
in the salinity of the water; caused on the one hand by the ebb and flow 
of the tide, and on the other by the large volumn of fresh water from the 
river, which, forced back by the flowing tide, accumulates in the upper 
reaches, and, when the reflux takes place, rushes seawards with over- 
powering force, so that, during the later part of the ebb, and the early part 
