v 



l(j G. 0. Sårs. 



their maximum size, and, moreover, showed traces of disease, 

 they were taken up and preserved, after a careful drawing 

 of each had been made, when still alive. 



The movements of the animal are very vivacious, and 

 it is very unusual to see it resting in the same place for 

 any length of time. The movements are chiefly effected by 

 the rhythmical strokes of the legs, though the very flexible 

 tail may also assist in the movement. More frequently it 

 swims with its back upwards, and this is always the case 

 when it keeps on the bottom. On swimming through the 

 water, however, it is sometimes seen to turn over, and when 

 it reaches the surface, the belly is generally turned upwards. 

 At other times it is seen climbing' the stems and branches 

 of the aquatic plants with great dexterity, in search of food, 

 twisting its extremely flexible body in all directions. When 

 in motion, the 1st pair of legs are extended laterally, with 

 the slender endites projecting from the sides of the carapace, 

 and pointing in different directions. It is therefore very 

 probable that these parts chiefly serve as tactile organs. The 

 next succeeding pairs, which are more or less incurved, are 

 used as powerful prehensile implements, by which the food 

 is seized and brought to the mouth, whereas the posterior 

 pairs seem to be wholly devoted to respiratory purposes. In 

 those legs which are exposed behind the carapace, the outer 

 appendages (exopodite and epipodite) are found, in the living 

 animal, to be in uninterrupted, rapid, vibratory movement, 

 whereby a constantly renewed current of water from behind 

 forwards is produced beneath the carapace. 



It is a curious fact that of the present species male 

 specimens were present in about the same number as female 

 ones, whereas in the European species, as is well known, 

 male specimens are extremely rare. 



