Ss / 
The remainder of the neck and the greater part of the 
swollen mass behind corresponds to the genital segment. 
The abdomen is represented by the terminal portion of 
the swollen part, and gradually tapers to a blunt end. 
The swollen region of the genital segment is abruptly 
bent into the form of the letter S (Plate IV., fig. 1). 
The appendages are rudimentary, the greater number 
being entirely absent. Those present are the first pair 
of maxillipedes placed at the apex of the head, immediately 
under the mouth, and four pairs of swimming feet at the 
anterior end of the narrow neck. ‘The swimming feet are 
exactly as they exist in the cyclops stage both in size and 
structure. The protopodite is two-jointed, the exopodite 
of the four pairs is two-jointed. The endopodite of the 
first two pairs is also two-jointed. The third and fourth 
pairs of feet have no endopodite. 
The external openings are, the mouth placed at the 
apex of the head, the openings of the oviducts situated 
on the ventral aspect of the S-shaped region, and the anus 
at the blunt apex of the abdomen (Plate IV., fig. 1, an.). 
The colour of the living animal is dark red, due to the 
contained blood. When removed from the fish and placed 
in sea water the colour changes to white. Lernea does 
not live long after being taken from the fish. The 
longest period observed was about twelve hours. They 
are simply inert sacs quite incapable of movement. 
Occasionally the parasites are covered with colonies of 
hvdroids which sometimes entirely obscure them. The 
exoskeleton consists of a chitinous cuticle moderately thin 
and soft in the region of the swollen part, but thick and 
hard on the neck and head. 
Immature Lernwa branchialis living on the apex of the 
gill filaments of the flounder (Plate IV., figs. 3, 4, and 5) 
are cyclopoid in appearance. The animal is oval in trans- 
G 
