49 



Fam. 8. Scolecithricidae. 



Characters. Body of somewhat varying form, sometimes rather short and 

 robust, sometimes more slender. Cephalosome coalesced with the 1st pedigerous 

 segment, front carrying below 2 more or less distinct soft tentacular appendages. 

 Last 2 segments of metasome generally united. Urosome, as a rule, short, 4-arti- 

 culate in female, 5-articulate in male. Caudal rami short, with only 4 apical setse. 

 Eye small, simple. Anterior antennae more or less slender, 19 23-articulate, 

 with the outer 2 joints not distinctly defined; those in male transformed in the 

 usual manner. Posterior antennae with the outer ramus 6-articulate. Masticatory 

 part of mandibles and maxillae not very strong. Anterior maxillipeds compara- 

 tively small, with the setae of the terminal part transformed to delicate sensory 

 appendages, which are either all vermiform or some of them pedicellate, termin- 

 ating in a knob-like dilatation. Posterior maxillipeds slender, with the terminal 

 part reflexed. Oral parts in male more or less transformed. Natatory legs 

 powerfully developed, and generally spinulous on the hind face, inner ramus of 

 1st pair uniarticulate, of 2nd pair biarticulate, of 3rd and 4th pairs 3-articulate. 

 5th pair of legs sometimes wanting in female, but more frequently present, though 

 of rather simple structure ; those in male comparatively slender and rather asym- 

 metrical. 



Remarks. In this family I propose to comprise the several forms referred 

 by other authors to the genus Scolecithrix of Brady. There cannot, in my opinion, 

 be any doubt that some at least of these forms ought to be generically separated 

 from each other, as they differ in several very essential characters, e. g. in the 

 presence or absence of the last pair of legs in the female, and in the structure 

 of these legs in the male. Another character has been called attention to by 

 Mr. Th. Scott, viz., the different development of the terminal appendages to the 

 anterior maxillipeds. I think we must admit at least 4 different genera, viz., 

 Scolecithrix, Brady; Lophothrix, Giesbrecht; Amallophora, Scott, and Scolecithri- 

 cella, G. 0. Sars. Of these genera, only the 2 last-mentioned are represented in 

 the fauna of Norway. 



8 Crustacea. 



