258 
Part III. — Tenth Annual Report 
ing from the base, but the terminal claw of the same appendage in Th. 
harpactoides is provided with only a single delicate seta. From Th. 
mysis this species is at once distinguished by the form of the fifth feet in 
both 9 an( i & specimens. 
Scutilidium fasciatum (Boeck). 
1864. Porcilidium fasciatum, Boeck, c Oversigt Gorges Copepoder,' 
p. 56. 
1868. Aspidiscus fasciatus, Norman, 'Brit. Assoc. Report,' p. 298. 
1880. Scutilidium fasciatum, Brady, 'Monog. Brit. Copep.,' ii. p. 
178, pi. lxviii. fig. 11 ) pi. lxix. figs. 1-9. 
Habitat. — In a shore-gathering from Dunbar, collected by Mr Peter 
Jamieson, assistant naturalist. This and S. tisboides may be distin- 
guished from most other British Copepoda by the peculiar form of the 
first pair of feet. 
Cylindropsyllus Icevis, Brady (PI. XIII. figs. 1-18.) 
1880. Cylindropsyllus lasvis, Brady, 'Monog. Brit. Copep.,' vol. 
iii. 
Female. — Length 1 *4 mm. Animal elongate, cylindrical, cephalo-thorax 
five-jointed, not distinctly separated from the abdomen, which is four- 
jointed ; the first body segment about as long as the next two together ; 
forehead produced into a sharp rostrum. Anterior antennae short, scarcely 
longer than the first body segment, seven-jointed, the proportional length 
of the joints as in the formula 
10 • 22 • 9 • 6 • 5 • 4 • 8 
1« 2 * 3 ' 4 • 5 ' 6 '7 
Sparingly setiferous, a long slender olfactory appendage springs from the 
end of the fifth joint. Posterior antennae two-jointed, basal joint long 
and moderately stout, bearing near the proximal end a very small one- 
jointed secondary branch which is furnished with one long terminal setae ; 
the last joint of the primary branch is armed with several spiniform hairs. 
Three of those which spring from the extremity of the joint are long and 
bent near the middle, where, on the outer one of the three, is a produced 
spine-like process, which looks to be a continuation of the straight proximal 
half of the hair. Mandibles well developed, consisting of a stout biting part 
furnished with several small teeth, and a small one-branched palp bearing 
three moderately long terminal hairs. There is anterior to the mandibles 
a peculiar organ possessing at its anterior edge two subtriangular append- 
ages which are crenate on the outer margin and measure in breadth very 
nearly -01 mm. These subtriangular appendages resemble somewhat the 
sucking disks o-i the forehead of Caligus and may function as such, 
but this is very doubtful. Our dissection shows a slender muscle 
extending upwards and, terminating between the two appendages where 
it becomes dilated, and seems to connect the two. 
The maxillae (fig. 7) consist of flattened plates, ciliate on the inner 
margin, the cilia being bounded externally by a small spine. Anterior 
foot-jaws one-jointed, small, and furnished with one or two marginal pro- 
cesses ; posterior foot-jaws stout, bearing a prominent, somewhat clawed 
terminal spine, and two marginal setiferous processes. Outer branches of 
first four pairs of swimming feet three-, inner branches two-jointed ; fifth 
pair one-branched, foliaceous. (For description of swimming feet, caudal 
stylets, and setae see ' British Copepoda,' iii. p. 30.) Ovisacs two, each con- 
taining three large ova arranged as shown in the figure. The integument 
