176 
Records of the Australian Museum (2014) Vol. 66 
Biometric data. Females (N = 6): maximum length (L m ax) 
mean 0.92 mm, range 0.90-0.98 mm, body length (L U rs) 
mean 0.85 mm, range 0.82-0.86 mm; cephalosome width 
(W) 0.65 mm, range 0.63-0.66 mm, length 0.47 mm; rostrum 
width (R) 0.13 mm; genital double-somite width 0.35 mm, 
length 0.20 mm; caudal ramus width 0.08 mm (V\ down 
ramus), length 0.16 mm. 
Ratios: L U rs/W1.3, Lmax/W1.4, cephalosome 55% of 
L urs , W/R5.0; genital double-somite w/11.75, width 54% of 
cephalosome, anterior lobe 77% of lateral border, posterior 
lobe 23% of lateral border; caudal ramus 19% of L U rs, 1/w 
2.0, Hicks’ index for a 86%, for p 60%. 
Males (N =8): maximum length (L m ax) 0.72 mm, range 
0.70-0.76 mm; cephalosome width (W) 0.55 mm, range 
0.49-0.57 mm, length 0.32 mm; rostrum (ventral) 0.07 mm; 
caudal ramus width 0.055 mm, length 0.065 mm; antennule 
length (fully extended) 0.20 mm; spermatophore 0.18 x 
0.04 mm. 
Ratios: LmaxAV 1.3, cephalosome 43% of Lmax, W/R 
7.8; caudal ramus 1/w 1.15, Hicks’ index for a 68%, for (3 
60%; antennule 27% of body length, antennule segment 2 
34%, segments 3+4 34%, dactylus 24%, aesthetasc 78% of 
antennule length; spermatophore 25% of Lmax. 
Description. Adult females (Fig. 1A): colourless or very 
pale amber, heavily sclerotized regions brown. Body outline 
elliptical, truncated anteriorly with convex bulge above 
rostrum, rostrum (Fig. 3H) partly obscured by anterior bulge. 
Hyaline border clear, 12—14 pm wide. Rows of conspicuous 
pits (3 pm) surrounded by rim of thickened cuticle ornament 
dorsal surface of cephalosome, metasome, genital double¬ 
somite and P5s (Plate ID, p. 172), conspicuous cuticular ridge 
runs parallel to edge of cephalosome and medial to the blocks 
of microtubules (Fig. 1A; Plate 2B, p. 173). Numerous (> 100) 
sensilla form a regular pattern on the dorsal surface of the 
cephalosome, metasome segments and genital double-somite 
(Plate 1A, p. 172; Fig. 1C). Some resemble setae, but most 
are short tubular structures with a basal collar that project 
through holes in the cuticle (Plate 2B,C, p. 173). Two massive 
cuticular outgrowths resembling honeycomb 30-50 pm high 
(Fig. 1A, 4C; Plate 1A,B,C, p. 172) are present on dorsal 
midline of cephalosome. Individual cells range from 5^10 
pm in diameter and have very thin walls (<0.5 pm). Similar, 
but smaller, cuticular outgrowths are present on metasome 
3 and genital double-somite. On either side of anterior half 
of cephalosome there are eleven blocks of microtubules 
close to hyaline border (Figs 1A, 4E left side; Plate 2A-D, 
p. 173). Each block contains 80-100 tubules and each tubule 
is 0.75 pm in diameter, 2.5 pm high and has a lumen 0.15 
pm in diameter (Plate 2D, p. 173). Labrum without ridge 
plates, posterior edge with three or four setules at lateral 
comer (Fig. 5D). Genital double-somite about half width of 
cephalosome (Fig. 1C, note that width is distorted in drawing 
by pressure of coverglass), a distinct notch marks boundary 
between anterior and posterior lobes, one sensillum mid-way 
along edge of anterior lobe, posterior lobe about l A length of 
genital double-somite, (in normal view posterior lobe appears 
pointed, but when laid flat it is rounded, Fig. 1C), setules on 
posterior lobe smaller than those on anterior lobe (Fig. IE). 
Dorsal surface pitted, many seta-like sensilla present plus 
area of honeycomb cuticle in midline. Posterior arch deep, 
surrounds about l A of caudal furca. Genital opening straight 
(Fig. 21). Metasome segment 4 with fimbriate setules on 
posterior edge of sternum. Caudal rami broad, elongate (Fig. 
IF), medial edge straight with setules down length, lateral 
edge slightly convex with few setules distally. Seta T1 small 
pinnate, deeply recessed, posterior border slightly convex 
with three very large pinnate setae (T2, T3 and T4) evenly 
spaced (Fig. ID). Dorsal surface with two longitudinal ridges 
and some net-like markings, a and (3 setae very long (about 14 
length of ramus). Seta on first segment of antennule pinnate. 
Stmcture and setation of mouthparts and ambulatory limbs 
typical of family. Basis of antenna with row of triangular 
setules (Fig. 2A), exopod with six plumulose setae, segment 
2 of endopod with three lateral setae, geniculate setae plain, 
claw comb-like. Mandible with small group of setules on 
anterior lobe (Fig. 5C). Maxillule with single bulbous seta 
on exopod (Fig. 2B). Maxilla as in Fig. 2D. Maxilliped coxae 
do not meet in midline (Fig. 2C), coxa with fimbriate border, 
fimbriate process greatly reduced in size and represented by a 
bunch of fine fimbriate setules (Fig. 2H). Endopod of PI with 
small area of denticulate setules at lateral end of fimbriate 
crescent (Fig. 5E). P2 endopod with strong proximal setules 
on segment 1, serrulate spinous seta on segment 3 % length 
of endopod (Fig. 5B). Serrate spinous seta on segment 2 of P3 
endopod (Fig. 2F) shorter than endopod (0.7:1), large serrate 
spinous seta on segment 3 very much longer than endopod 
(1.7:1). P4 endopod segment 1 without internal seta (Fig. 
2G), seta on segment 2 and first internal seta of segment 3 
thin, straight spinous. Exopod of P5 lanceolate (Fig. 2E), 
dorsal surface with rows of pits, one sub-terminal seta and 
two apical setae, border setules long (25 pm). Females carry 
10 eggs per brood. 
Adult males (Fig. IB). Outline of cephalosome a sharply 
truncated hemi-ellipse, convex in midline above rostrum, 
rostrum rounded (Fig. 5 A), lateral angle of antennule sockets 
project forward, shoulder with epaulet and several cuticular 
serrations (in ventral view, Fig. 5A), hyaline border starts 
at epaulet. No microtubules on border of cephalosome (Fig. 
4D), ducts from marginal glands open individually dorsal 
to hyaline border. Colour, pits, ridges, sensilla and massive 
dorsal cuticular honeycomb as described for female. Caudal 
rami rectangular (Figs 3A, 5F), lateral edge convex, with 
setules at posterior end, posterior border slightly convex 
with fine setules, setules down medial edge, dorsal surface 
with longitudinal ridge and net-like markings, a and (3 setae 
very long (almost length of ramus), inserted very close 
together about l A way down ramus. Terminal seta T1 small, 
pinnate, recessed at lateral corner, T2, T3 and T4 large 
pinnate setae evenly spaced. Antennule (Fig. 3E) without 
denticle on segment 3, four or five closely grouped finger-like 
processes (not cuticular denticles) on segment 4 (Fig. 3F), 
dactylus shorter than segment 3+4, with small hook at end of 
segment 5 (Figs, 3E, G), aesthetasc long (about 3 A length of 
antennule), divided into three sections by two constrictions. 
Terminal segment of P2 endopod with two plumose setae 
and one serrulate spinous seta (Fig. 3C). Segment 1 of P4 
endopod without internal seta, setae on segments 2 and 3 
plumose (not spinous). P5 exopod acutely trapezoid (apical 
angle 50°) with rows of pits on dorsal surface (Fig. 3B), first 
(lateral) seta with five strong ventral setules, each terminal 
seta with two or three setules at its base (Fig. 3D). 
