14 



G. O. SARS. M.-N. Kl. 



in the ventral or dorsal view of the animal (fig. 9), is very conspicuous, ex- 

 tending straight outwards. 



The tail (fig. 12) is not very large, and has dorsally 3 small pro- 

 cesses, the lower 2 of which are tipped with a bundle of hairs. The 

 terminal part is rather narrow, as compared with that in other species, 

 and nearly of uniform breadth throughout, with the dorsal margin in the 

 greater part of its length nearlj^ straight, and only in its outmost part 

 gently curving towards the base of the terminal claws. The latter are 

 rather strong and somewhat curved, but perfectly smooth. The anal den- 

 ticles are only 6 on each side, gradually somewhat increasing in length 

 distally. They are rather feeble and somewhat curved, terminating each 

 in a very sharp point. The caudal setae are comparatively slender, being 

 nearly as long as the terminal part of the tail, and are finely ciliated. 



The ova in the matrix, in individuals of the earlier generations, are 

 sometimes rather numerous, causing the dorsal part of the carapace to be 

 strongly arcuate. In specimens of the later generations, their number is 

 generally restricted to 2, lying side by side (see figs. 9 & 10). The 

 yolk-mass is at first bkiish green, becoming gradually paler, and at last 

 assuming a reddish orange hue. 



The ephippium, as in the other species, is oval and contains but a 

 single egg-ampulla placed longitudinally. 



The adult male (fig. 14) is much smaller than the female, scarcely 

 exceeding in length 0,38 mm. It has the carapace narrower and more 

 regularly quadrangular, the dorsal margin being nearly quite straight. 

 The lower edges of the valves are slightly sinuatcd in front of the middle, 

 where they are fringed with fine hairs. The head does not differ much 

 in its shape from that in the female, except that it is perhaps a little more 

 erect. Male specimens are, however, easily distinguished from females 

 of same size by the structure of the antennulæ. These appendages 

 (fig. 15) are much more fully developed, extending far beyond the rostrum, 

 and arc moreover each provided with a distinct sctiform flagellum arising from 

 the tip in front of the fascicle of olfactory papillae. The ist pair of legs 

 have each a distinct, though not very strong claw, and terminate in a 

 long setiform flagellum, often extending beyond the valves. The tail does 

 not seem to differ materially from that in the female. 



The colour is somewhat variable. In females of the earlier genera- 

 tions it is often found to be more or less orange, turning to light reddish ; 

 whereas in specimens of the later generations it is generally paler, yel- 

 lowish. The males are, as a rule, of a more pronounced reddish colour 



