KONGL. SV. VET. AKADEMIENS HANDLINGAK. BAND. 22. N:0 7. 405 



The first pair of perceopoda (PI. XVII, fig. 31 and 32) are the smallest of all the 

 pairs. The femur is very narrow, a little broader below than above, with the margins 

 smooth; it is longer than the three following joints together. The genu is considerably 

 longer than broad. The tibia is shorter than the genu. The carpus is nearly as long 

 as the two preceding joints together, and is almost cylindrical. The metacarpus is fully 

 as long as the two preceding joints together, broad at the base, and tapering evenly towards 

 the apex; the hind margin is fringed with short, slender bristles. The dactylus is stout, 

 conical, more than a third part as long as the metacarpus; it is provided with a secondary 

 tooth near the apex, and is pectinated along the hind margin. 



The second pair (PI. XVII, fig. 33) are longer than the first, and reach a little 

 beyond the apex of the tibia in the third pair. The femur is broadly dilated, about 

 half as broad as long, and considerably longer than the three following joints together. 

 The genu is longer than broad. The tibia is shorter than the genu. The carpus is 

 thicker than in the first pair, cylindrical, and fully as long as the two preceding joints 

 together. The metacarpus is considerably longer than the two preceding joints together, 

 broad and swollen at the base, and rapidly tapering towards the apex. The dactylus is 

 slender, feebly curved, without secondary tooth, and about a fifth part as long as the 

 metacarpus. Glands are well developed, especially in the femur. 



The third and fourth pairs (PI. XVII, fig. 34 and 35) are similar in shape and 

 subequal in length.' The femur is narrow, a little broader below than above, and is 

 much longer than the three following joints together. The genu is longer than broad. 

 The tibia is longer than the genu; the hind margin is smooth in the third pair, but 

 armed with two or three broad teeth in the fourth pair. The carpus is fully as long 

 as the two preceding joints together; the hind margin is armed with four low, broad teeth. 

 The metacarpus is as long as the carpus, and has the hind margin minutely serrated. 

 The dactylus is slender, feebly curved, and more than a third part as long as the 

 metacarpus. 



The fifth pair (PI. XVII, fig. 36) are much longer than the head and person 

 together. The femur is dilated, broader below than above, and more than twice as long 

 as it is broad below; the lower half of the front margin is convex and more or less 

 distinctly serrated. The genu is about as long as broad; the lower front corner is sharp- 

 pointed. The tibia is as long, but twice as broad, as the genu, with the lower front and 

 hind corners sharp-pointed. The carpus is elongate-ovate, as long as, or longer than, 

 the femur; the front margin is furnished with ten to eighteen larger and smaller teeth, 

 varying in order, as shows the diagram above p. 402; the apical tooth is two-pointed; 

 the hind margin is smooth, with the lower corner sharp-pointed. The metacarpus is 

 slender, linear, and fully as long as the carpus in adult animals; in younger it is much 

 shorter. The dactylus is long and feebly curved; it is about a third part as long as 

 the metacarpus in adult animals, in younger it is more than half as long as the meta- 

 carpus. 



The sixth, pair (PI. XVII, fig. 37) reach beyond the apex of the carpus in the fifth 

 pair. The femur is dilated, more than twice as long as broad, and about as long as 

 the three following joints together; the front margin is convex, with four or five low 



