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one. True, the presence of 3 pairs of apparently similarly constructed ambu- 

 latory legs would seem to approach the Bairdiince closer to the Cytheridse 

 than to the Cypridce, in which, as a rule, only a single pair of true ambula- 

 tory legs are found. On a closer comparison with the Cyprids treated of in 

 the preceding pages, it is however easily understood that the 1st of those 

 pairs answer to the maxillipeds in these Cypridae, and that their pediform 

 appearance is only due to an access of growth of the palps, rendering them 

 adapted for locomotion. These legs moreover exhibit a true Cyprid character 

 in the presence, at their base, of a well developed vibratory plate, never found 

 in any of the Cytheridae. Nor can the perfect similarity of the 2 last pairs of 

 legs be regarded as decisive for a classing of the present subfamily within 

 the Cytheridae. For in the genus Paracypris, which unquestionably is referable 

 to the typical Cypridae, the posterior legs only very little differ in structure 

 form the anterior ones and may indeed assist them in the crawling movements 

 of the animal 1 ). Another character may here be named, which seems to 

 remove this subfamily from the Cypridce, viz., the absence of ejaculatory tubes 

 in the male. In the Pontocyprince however, as stated above, these tubes are 

 so imperfectly developed, as to be nearly said to be obsolete. After all, I 

 think that the arrangement here proposed may be found to be acceptable. 



The present subfamily as yet only comprises 3 nearly-allied genera, 2 of 

 which are represented in the Fauna of Norway. 



Gen. 6. Bythocypris Brady, 1888. 



Generic Characters. Shell more or less compressed, of oval or reniform 

 shape, and almost bare of hairs, edges unarmed. Both pairs of antennae com- 

 paratively shorter and stouter than in the type genus; the anterior ones with 

 the apical setae far less prolonged. Posterior antennae with the penultimate 

 joint moderately prolonged; apical claws very slender, but unequal in length. 

 Anterior lip only sligthly prominent and obtuse at the end. Mandibles with 

 the masticatory part not much expanded, but coarsely dentate; branchial 

 appendage of palp comparatively small, with only 3 setae, one of which 

 is much elongated. Maxillae with the masticatory lobes narrowly produced, 

 palp scarcely larger than these lobes and uniarticulate; vibratory plate exhibiting 

 at the base a well marked expansion edged with numerous very thin and 



') Cfr. the description of this genus farther on. 



