10 G. 0. Sårs. 



other parts of the leg, which all exhibit a very delicate 

 membranous structure. Inside the endopodite, numerous 

 muscular bands are seen extending in different direc- 

 tions. Some of them join the exopodite, which is the 

 most freely movable appendage, being found now extended 

 in the axis of the leg, now considerably incurved beneath 

 the terminal lobe of the endopodite. Between the muscles 

 a number of opaque, somewhat stellate patches are seen 

 scattered over the greater part of the endopodite, These 

 patches are produced by a corresponding number of cross- 

 bars connecting the 2 lamellae composing the leg, and thereby 

 a system of internal hollows is formed, in which the blood 

 circulates. A similar structure may also be found on other 

 parts of the leg, and especially very distinctly in the epipodite. 



The above description applies to the greater number of 

 the legs. Only the first and last pairs exhibit some minor 

 differences, to be mentioned below. 



In the 1st pair the exopodite is considerably smaller 

 than in the others, not extending at all beyond the terminal 

 lobe of the endopodite, which appears rather broad in 

 proportion to its length (see fig. 4). 



The last pair of legs (fig. 6) differ from the others in 

 the fact, that the terminal lobe of the endopodite is some- 

 what less developed, whereas the exopodite is fully as large 

 as in the preceding pairs. Moreover, the inner lobes of the 

 endopodite are considerably reduced in size, and only supplied 

 with scattered and rather short bristles. The basal plate 

 is likewise comparatively smaller than on the other legs; 

 and finally, the epipodite has lost its spongeous character, 

 and assumed a structure similar to that of the basal plate, 

 its terminal edge even being divided into a number of 

 distinct serrations. 



