20 G- O. Sars. 



prominent, and is evenly rounded; and the ventral edge of the 

 head forms only a slight convexity at the insertion of the 

 antennulæ, without being defined by any perceptible notch 

 from the base' of the labrum. Of the fornix, only a slight 

 trace is found as a somewhat elevated ridge above the base 

 of the antennæ. 



The eye is of moderate size, and provided with a 

 number of well-defined crystalline bodies. The ocellus, as 

 in the other species of the genus, is wholly absent. 



The antennulæ (fig. 2) are comparatively short, scarcely 

 exceeding half the length of the head, and exhibit a some- 

 what fusiform shape, being distinctly dilated in the middle. 

 They are, as in the other species, freely mobile, and are 

 clothed posteriorly with delicate cilia. Anteriorly each 

 antennula carries a single sensory bristle, occurring somewhat 

 nearer to the base than to the tip, and the latter has a bundle 

 of very small olfactory papillæ. 



The antennæ are powerfully developed, and of the 

 structure characteristic of the genus. The scape is very 

 massive and strongly muscular, and is provided near the 

 base outside with 2 juxtaposed and rather long sensory 

 bristles, which, especially in the dorsal or ventral views of 

 the animal, are very conspicuous; at the end, another sensory 

 bristle is seen projecting between the bases of the rami. 

 Both the outer part of the scape and the rami are densely 

 hairy, and the natatory setæ finely ciliated. 



The 1st pair of legs (fig. 3) are constructed in the very 

 same manner as in the European species, M. brachiata, and 

 differ markedly from those in M. paradoxa, by the sub- 

 apical seta being quite simple and finely ciliated, like most 

 of the other setæ, whereas in M. paradoxa, according to 



