254 Part IIL.-—Tenth Aa Re; pon 
bb peo oe — 
1? 2:33 eae eee 
The fourth joint is produced so as to form the cee of a lone and Sie 
sensory filament. Ali the joints except the first are more or leg setiferous. 
Posterior antennz threejointed, 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). Maxille 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 im the one and two in the other, with a clear 
space between. ‘The last three joints, which are very small, are furnishel == 
with a number of small sete. Posterior foot-jaw three-jointed, last joint == 
forming a base for a moderately long terminal claw and a small seta; ing 
a plumose seta springs from the inner margin, and near the middle of the ange 
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 Tetragoniceps 
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 sete, 
the inner terminal seta being plamose, the others plain. A strong muscle 
extends down the exterior side and across the extremity, and sends off 
ae branches to the marginal sete. Inclosed within the feet were a 
va a ‘number of ova, having appwently no other covering than that of the 
Su, enclosing large foliaceous plates. Abdomen fivejointed ; the posterior 
ventral margin of the third segment is produced so as to form a prominent 
fold which extends about halfway 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 séta. 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. Rare. The nine-jointed anterior antenna, 
with the strong claw-like process of the second joint, together with the 
remarkably large, foliaceous fifth feet, render this a well- marked | 
“species. 
wir 
Tetragoniceps incertus. \ (Pl. XII. figs. Te 17). 
Female.—Body elongate, cylindrical ; length, exclusive of caudal sete, 
1 mm. First cephalo-thoracic segment about as long as the next two 
together, forehead produced into a sharp-pointed rostrum. Anterior 
ante nne about as long as the first body segment, seven-jointed, the 
proportional length of the joints as shown in the formula 
20° 18 Ao pied 5 Oe 
| 19% Bis oy 
All the joints except the first sparingly setiferous; a moderately long 
olfactory filament springs from the end of the fourth joint. Posterior : 
‘antenne short, two- (or three-?) jointed, and possessing a very small one- 
_ jointed secondary branch which bears two terminal sete. The apex of the cog 
last joint of:the primary branch is furnished with five setze, 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 ab 
the base, the apex truncate, and armed with several blunt- pointed teeth; — 
‘ mandible palp one-branched, long, and slender. Anas small, simple, with 
