58 



having a similar vermiform shape. Natatory legs with the same number of joints 

 in the rami as in that family. Last pair of legs wholly absent in female, in 

 male of extraordinary size and very complicated structure. 



Remarks. This family bears a close resemblance in several points to the 

 Scolecithricidw, yet differing very materially, both in the uniform appearance of 

 the anterior antenna in the two sexes, and in the enormous development and 

 peculiar structure of the last pair of legs in the male. It contains as yet but a 

 single genus, to be described below. 



Gen. 15. DlaiXiS 1 ), G. 0. Sars, n. 



Syn: Scolecithrix, Scott (pai-t). 



Generic Characters. Body not very slender, with the anterior division 

 much vaulted in front. Rostral prominence simple, deflexed, without any tentacular 

 filaments. Last segment of metasome in female with the lateral parts lamellarly 

 produced. Urosome comparatively short, genital segment in female produced 

 dorsally. Eyes subventral, placed close together, though well defined in the middle. 

 Anterior antennae 24- articulate, with some of the setse of the terminal joints 

 ciliated. Posterior antennae with the outer ramus very large, 6-articulate, last 

 joint much the longest. Mandibles slender, with the masticatory part scarcely at 

 all expanded, inner ramus of palp poorly developed. Anterior maxillipeds with 

 the terminal appendages very delicate and all of the same appearance. Posterior 

 maxillipeds with the terminal part unusually short and reflexed. Natatory legs 

 slender, without any spinules on the hind face, terminal spine of outer ramus in 

 the 2nd to 4th pairs coarsely denticulate outside. Last pair of legs in male 

 transformed to a powerful grasprng organ, attached to the body by a thin and 

 flexible stalk, and composed of a large and tumid basal part and 2 rami of nearly 

 equal length, the right one forming the immediate continuation of the basal part, 

 the left one beig movably articulated to its posterior face. 



Remarks. This genus is established to include the peculiar form described 

 by Mr. A. Scott as Scolecithrix hibernica, which species most certainly does not 

 belong to Brady's genus. In addition to the typical form, another nearly-allied 

 species has been recorded by Th. Scott as Scolecithrix pygmcea. Only the first 

 of these species belongs to the fauna of Norway. 



*) Nomen proprium. 



