v9 
conical tube of the mouth, and consist of two parts. The 
basal joint is cylindrical. The second joint is flattened, 
and terminates in a broad blade, which is serrated on the 
inner margin. 
The single pair of maxille are placed at the base of the 
mandibles. They consist of two lobes, one of which is 
very small. The larger lobe has two moderately long 
setee at its apex, the smaller one has one seta. 
The first pair of maxillipedes are placed immediately 
behind the mouth. They consist of four joints, the last 
joint being furnished with a strong claw. The basal 
joint has two short hooks near its apex. 
The second pair of maxillipedes in the female are rudi- 
mentary, and are represented by a minute knob. In the 
male they are composed of two joints, the apical one being 
in the form of a powerful claw. It is by the aid of the 
second maxillipedes that the male grasps the female 
during copulation. 
The first pair of swimming feet consist of a two-jointed 
protopodite, an endopodite and an exopodite, both two- 
jointed. The apical joints of the endopodite and the 
exopodite are furnished with long plumose sete on their 
inner margin and apex. This pair of feet is attached to 
the posterior end of the cephalo-thorax. 
The second pair of swimming feet is attached to the 
first free thoracic segment, the third pair to the second 
free thoracic, and the fourth pair to the third. These 
free segments really represent the second, third and 
fourth thoracic segments, the first being a part of the 
cephalo-thorax. The second pair of swimming feet in 
every respect resemble the first pair. The protopodites 
of the third and fourth pairs are two-jointed; the endo- 
podites in both pairs are absent. The exopodites are 
similar to those of the first and second pairs. The fifth 
