100 
pair of feet is represented by minute papille. The caudal 
stylets are very short, and furnished with three or four 
short plumose sete at the apex. 
The external openings are the mouth, the vulye, the 
openings of the vasa deferentia and the anus. 
The mouth is situated on the ventral surface of the 
cephalo-thorax, at the apex of a conical tube, composed 
of the upper and lower lips fused together. In the very 
early cyclops stage the lips are not fused. The vulve and 
openings of the vasa deferentia are placed at the posterior 
angles of the genital segment. The anus is at the apex of 
the abdomen, in the middle line. The vulve open into 
the receptacula seminis, which are in direct communi- 
cation with the oviduets. 
The whole of the genital segment and abdomen in the 
female is marked by fine transverse lines. The colour, 
which is arranged in patches, varies from dark violet to 
hight red. 
ALIMENTARY CANAL. 
In the adult the mouth opens into the intestine, which 
probably acts as the stomach, the cesophagus and true 
stomach having disappeared in the metamorphosis of the 
cephalo-thorax. The intestine is at first narrow where 
it passes through the neck, then it widens considerably in 
the swollen part of the genital segment, contracting 
shghtly in the abdomen, and finally terminates in a short, 
narrow rectum leading to the anus (Plate V., Fig. 4). 
The intestine is lined with a single layer of nucleated 
cells. Attached to this layer, and in some cases embedded 
in it at irregular intervals, are large cells filled with fine 
granular material. In some parts these large cells are 
grouped together two and three rows high. In other 
parts they are quite free (Plate V., figs. 5 and 6). The 
layer supporting the nucleated cells appears to be com- 
