254 
Part III. — Tenth Annual Report 
; 27 ■ 10 ■ 7 • 5 • 3 • 3 • 2 • 2 • 11 
P 2 " 3 • 4 • 5 * 6 ' 7 • 8 ' 9* 
The fourth joint is produced so as to form the base of a long and stout 
sensory filament. All the joints except the first are more or less setiferous. 
Posterior antennae three-jointed, the joints subequal; a small secondary 
one-jointed branch springs from the end of the first joint. Mandible 
palp distinctly two-branched — one of the branches much larger than the 
other (fig. 22). Maxillae with a broad biting part and a four-lobed 
branchial appendage. Anterior foot-jaw five-jointed ; the broad first and 
second joints bear five marginal, digitiform, setiferous lobes arranged in 
two groups — three lobes in the one and two in the other, with a clesr 
space between. The last three joints, which are very small, are furnished 
with a number of small setae. Posterior foot-jaw three-jointed, last joint 
forming a base for a moderately long terminal claw and a small seta ; 
a plumose seta springs from the inner margin, and near the middle of the 
second joint, anterior to the plumose seta, are a number of fine marginal 
cilia. The first joint is furnished with two subterminal plumose hairs. 
The first four pairs of swimming feet are , nearly as in Tetragonieeps 
maleolata. The fifth pair, which are one-branched, are in the form of 
large, foliaceous concave plates, the length of which is about one-third the 
length of the whole animal (fig. 30). Their breadth is about equal to half 
their length. The extremity and outer margin are provided with a few setse, 
the inner terminal seta being plumose, the others plain. A strong muscle 
extends down the exterior side and across the extremity, and sends off 
branches to the marginal setae. Inclosed within the feet were a 
number of ova, having apparently no other covering than that of the 
enclosing large foliaceous plates. Abdomen five-jointed; the posterior 
ventral margin of the third segment is produced so as to form a prominent 
fold which extends about half-way over the next segment. Caudal 
stylets about as long as the last abdominal segment, and having the outer 
margin nearly straight and the inner strongly sigmoid ; each stylet bears 
a long terminal seta, the base of which is considerably dilated, and a few 
very small hairs, as shown in figure 32. No males were obtained. 
Habitat. — Off St Monans. Eare. The nine-jointed anterior antennae, 
with the strong claw- like process of the second joint, together with the 
remarkably large, foliaceous fifth feet, render this a well-marked 
species. 
Tetragonieeps incertus. (PI. XII. figs. 1-17). 
Female. — Body elongate, cylindrical ; length, exclusive of caudal setae, 
1 mm. First cephalo-thoracic segment about as long as the next two 
together, forehead produced into a sharp-pointed rostrum. Anterior 
antennae about as long as the first body segment, seven-jointed, the 
proportional length of the joints as shown in the formula 
20 • 18 • 12 • 7 ' 4 • 5 • 8 
1 • 2 - 3 • 4 ■ 5 • 6 • 7 * 
All the joints except the first sparingly setiferous ; a moderately long 
olfactory filament springs from the end of the fourth joint. Posterior 
antennae short, two- (or three- ) jointed, and possessing a very small one- 
jointed secondary branch which bears two terminal setae. The apex of the 
last joint of the primary branch is furnished with five setae, the three 
longest of which are bent near the middle, the outer one of the three 
having a small forward-directed spine at the bend. Mandible dilated at 
the base, the apex truncate, and armed with several blunt-pointed teeth ; 
mandible palp one-branched, long, and slender. Maxillae small, simple, with 
