224 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



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 maxillae 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 

 setse 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 setse 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 



