straight prominence clothed at the somewhat obtuse point with small spikes. 

 Chief piece of the copulatory apparatus abruptly curved upwards, with the 

 outer part narrow cylindric in shape and obtusely blunted at the tip. 



Colour not yet ascertained. 



Length of adult female 0.50 mm. 



Remarks. The above-described form so closely resembles young specimens 

 of P. orbicularis, as easily at the first sight to be confounded with that species. 

 On a closer examination, however, it may at once be distinguished by the far 

 less tumid shell, its dorsal or ventral aspects being indeed very different in 

 the 2 species (compare the figures here given). Moreover well marked diffe- 

 rences are found in the shape of the transformed left caudal lamella in the 

 male, as also in that of the chief piece of the copulatory apparatus. 



Occurrence. It is only recently that I have been aware of this species, 

 which may be not uncommon, at least on the south coast of Norway, as I 

 have succeeded in finding several specimens, both males and females, among 

 material collected partly at Risor, partly at Korshavn. 



Gen. 2. Polycopsis, G. W. Muller, 1894. 



Generic Characters. Shell of a somewhat similar shape to that in Polycope, 

 though more compressed, and having the anterior part of the ventral edges 

 distinctly serrate. Anterior antennae of a rather deviating structure, being com- 

 posed of a greater number of joints than in Polycope, amounting to 6 in all, 

 the first 2 of which are rather large and expanded, the 4 remaining joints 

 abruptly much smaller; 2nd joint much the largest and divided in front into 

 2 remarkable deflexed lappets, the distal one triangular in shape and highly 

 chitinised curving over the terminal part of the antenna. Posterior antennae 

 with the inner ramus in male distinctly prehensile, being armed at the end, in 

 front of the setae, with a slender recurved claw. Mandibles with the masticatory part 

 very narrow and imperfectly dentated at the end; distal joint of the palp some- 

 what differing in shape from that in Polycope, and having one of the apical setae 

 much stronger than the others, almost claw-shaped. Maxillipeds with the terminal 

 joint imperfectly defined. Caudal lamellae with the anterior corner bidentate. 



Remarks. This genus was established in the year 1894 by G. W. Muller, 

 to comprise the Polycope compressa of Brady & Robertson and an additional 

 Mediterranean species, P. serrata. It is especially distinguished by the peculiar 

 structure of the anterior antennae, and exhibits also some other well-marked 

 differences, as mentioned in the above diagnosis. Of the 2 as yet known 

 species, the one only is represented in the Fauna of Norway. 



