New Crustacea from the Swan River Estuary. 
51 
Appendages: Antennules reach about to the end of the 4th segment of 
the peduncle of the antennae. Basal segment the broadest, the second is 
only half as broad at the base, but expands slightly distally, and is covered 
with scattered setae. The next two segments are subequal and small. Fol- 
lowing these are two long segments, the distal of which is the longer. At 
the extremity is a small segment. There are apical setae and “olfactory 
filaments.” 
Antennae not as long as the body; the first three segments short and 
.subequal, the succeeding ones long and slender, the more distal longer than 
the other. Flagellum longer than the peduncle. Mandibles with cutting edge 
divided from the molar expansion by a deep cleft; palp well-developed. 
Maxilla 1 of the usual shape, outer lobe the longer and relatively stout, 
bearing about ten denticulate spines. The inner lobe is almost as long but 
is more slender; it is widest at a third of the distance from its base, and 
is armed with three spines terminally. Maxilla 2 of the usual shape with 
pectinate setae along the margin. Maxillipeds protecting the remainder of 
the mouth part and being rather lamelliform. From the coxa spring an 
epipodite and a large basis which is produced at its extremity, the inner 
side of which is lined by short setae, three of which at the end are stout 
and spinelike. The ischium of the palp is short. The merus is longer and 
fringed with setae and expanded distally. Carpus broader than long, propod 
narrow, expanding slightly at its extremity and curving inward, and is 
setose. Dactyl two-thirds as long as propod and ends in two stout setae. 
Pereiopod 1 with basis long, four times as long as broad; ischium about 
as long but narrower, merus expands antero-distally where it bears a single 
seta, a few others occurring on the anterior margin. The carpus is about 
the same size, but produced on the postero-distal angle which bears five 
spines, an apical cluster of four and one proximally on the margin. The 
propod is about as wide, its palmar margin with a convex expansion, fringed 
by small spinules. Two large spines occur at the base and several long setae 
over the surface. The dactyl bears a few fine setae and ends in two distinct 
spines, the outer of which is twice the length of the other. Pereiopod 2 about 
half as long as the body. The coxa is short but separate from the body; 
basis long and narrow, with setae on the hind margin and one anteriorly; 
ischium is similar in shape, not cjuite as long as the merus and narrower 
at the base though expanding somewhat at its middle length, with a few 
distal setae; carpus the same length as the ischium with a few scattered stout 
setae, mostly on the posterior border; propod shorter than the carpus and 
narrower, with four spines on the posterior border, and fine setae on the 
anterior; dactyl short and oblong, with two apical claws and two setae. 
Pereiopods 3 and 4 similar to the first except that the carpus and propod 
are elongated. Pereiopods 5-7 similar but considerably longer. 
Pleopod 1 modified to form an anal operculum which widens abruptly 
from its base and is rounded apically where a few setae are present. Pleo- 
pod 2 with basal protopod bearing- an inner flat branchial plate as the endo- 
pod; at its internal distal corner the branchial plate has a plumose seta. 
Exopod fused at its base with protopod. Its end segment is not quite as 
long as the basal, and both are fairly short and stout. The distal segment 
bears two stout apical setae. The whole exopod is fringed with delicate 
fine setae. Pleopod 3 very similar to pleopod 2 but has no apical seta on 
