54 



erior extremity with a single excessively prolonged hair, and along the frontal edge 

 with a dense fringe of peculiarly transformed and very delicate capillary appen- 

 dages. Eye wholly wanting. Both pairs of antennae short and stout, not adapted 

 for swimming (at least in female), the anterior ones with the basal part very 

 massive and sharply defined from the terminal part, the posterior ones with 

 the sensory appendage peculiarly transformed, pedicellate; some of the setae 

 on both pairs of antennae in male excessively prolonged and recurved. The 

 other limbs on the whole built on the same type as in the 2 preceding genera, 

 except that the branchial appendage of the mandibular palps is imperfectly 

 developed, and that the anterior legs are armed on the tip with 2 subequal 

 claws. Caudal rami comparatively small, conically tapered, with the apical cla 

 short and much curved. 



Remarks. This is a very distinct genus, differing in some respects con- 

 spicuously from the 2 preceding ones, though evidently referable to the same 

 subfamily. The genus was originally only founded on a single species described 

 by the present author in 1865; but in recent times several other species, more 

 or less agreeing with the typical one, have been added. Thus no less than 

 5 species, referable to this genus, have been recorded by G. W. Muller from 

 the gulf of Naples, and I have myself had an opportunity of examining a 2nd 

 Norwegian species very distinct from that at first described. 



5. Argilloecia cylindrica, G. O. Sars. 



(PI. XXIV) 

 Argilloecia cylindrica, G. O. Sars, Oversigt af Norges marine Ostracoder, p. 18. 



Specific Characters. Female. Shell very narrow, almost cylindrical in 

 shape, with the greatest height not nearly attaining half the length; seen 

 laterally, elongate oval or somewhat elliptical in outline, and scarcely broader 

 in front than behind, dorsal margin very little arched, ventral slightly sinuated 

 in the middle, anterior extremity rounded off, posterior abruptly blunted; seen 

 dorsally, narrow oblong, with the side-edges almost straight in the middle, and 

 the greatest width about equal to 2 /5 of the length, both extremities obtusely 

 pointed. Valves only little pellucid, with the surface smooth and polished; 

 inner duplicatures not very broad and of quite normal appearance. Anterior 

 antennae with the terminal part about the length of the basal one and distinctly 

 5-articulate. Posterior antennae with the outer part of the sensory appendage 

 disciform and sharply defined from the narrow attaching stalk; natatory seta? 

 very small and rudimentary, though present in the usual number. Branchial 



