530 



increasing in lengtli, and having tlie basal joint large and laminar. Branchial 

 lamellae comparatively small ; inciibatory lamellae narrow. Last pair of uropoda 

 not very mnch elongated, and having both rami uniarticulate and lanceolate 

 in form. Telson rather elongated and deeply cleft, each half bidentate 

 at the tip. 



Remarks. — The systematic position of this genus, established by 

 Sp. Bate, appears somewhat donbtfnl. Sp. Bate arranged it within his family 

 Phoxides, comprising a number of widel}^ different Amphipoda, and Boeck 

 regarded it as a member of the family LeiicothoidtB. Mr. Stebbing, having 

 restricted the familj- Leucothoida: to the genus Leucofhoe, retained the present 

 genus within the remnant of Boeck's family Leucothoidae, for which he 

 proposed the name of Eusiridce. The very fully developed accessory appendage 

 of the superior antennae, as also the more or less conspicuous sexual difference 

 in the structure of the gnathopoda, woiild, however, seem to remove tliis 

 geniTs rather widely both from the genus Eusirus and Rhachotyopis. and to 

 liring it nearer to the family Gammaridce, its species having, indeed, an unmistak- 

 able resemblance, at least in external appearance, to those of the genus 

 Cheir-ocratus. In the structure of the oral parts it differs, however, considerably 

 both from this genus and the other Gammaridse, and in this respect it 

 exhibits in fact a close resemblance to the genus Leucofhoe. Perhaps there- 

 fore, tlie genus should more properly be regarded as the type of a separate 

 family, and such a view is in fact supported by the existence of a verv 

 nearly-allied genus, IdimeUa, to be described below. The Gammarm 

 bisjnnosKS of Costa would seem to belong to the present genus, and Mr 

 Stebbing has added 2 new species from the Challenger Expedition. Anothei 

 species has recently been described by Mr. Norman as L. picfa. To th( 

 fauna of Norway belong 4 species, to be described below, one of wliich is 

 now for the first time established. 



26. Lilljeborgia pallida, Sp. Bate. 



(PI. 187). 



Gammarus palUdus, Sp. Bate, Brit. Assoc. Report 1856, p. 66. 



Syn: Gammarus brevicornis, Bruzelius. 

 " Iduna brevicornis, Boeck. 



Body rather stout and highly compressed, with the 2 anterio: 

 segments of metasome and the 1st of iirosome each produced dorsally to i 

 small dentiform projection. Cephalon scarcely attaining the length of thi 



