115 



adopted), for instance, T, gibla Kr0yer. It is however a true Parafhalestris as 

 proved both by the structure of the rostrum and that of the several appendages. 



Occurrence. Off the Finmark coast this form is by no means rare. 

 I found it, for instance, many years ago in considerable abundance at Vadso; 

 and in some samples taken by Mr. Nordgaard at Repvaag (Porsanger Fjord), 

 and kindly sent to me for examination, it was also rather common. Though 

 undoubtedly a true arctic form, it also occurs occasionally far out of the arctic 

 region, for instance in the outer part of the Trondhjem Fjord, at Bejan, and in 

 the Storfjord, inside Aalesund. A single specimen of this form was even taken 

 as far south as Grimstad, off the south coast of Norway. 



Distribution. Franz Josef Land (Scott), Polar Islands north of Grinnell 

 Land (2nd Fram Exped.). 



Gen. PhyllOthaleStriS, G. O. Sars, n. 



Generic Characters. Body somewhat compressed in front, more flattened 

 behind, with the cephalic segment very large and deep. Rostrum abruptly de- 

 flexed and apparently immobile, though defined from the cephalic segment by a 

 well market! suture. Epimeral plates of the 3 succeeding segments rather fully 

 developed. Urosome of moderate length, with the genital segment in female very 

 large and flattened. Eye large and of rather complicated structure. Anterior an- 

 tennce slender, 9-articulate; posterior ones less strongly built than in Parathalestris, 

 outer ramus biarticulate. Oral parts on the whole normal. 1st pair of legs of 

 a structure similar to that in Thalestris. Natatory legs likewise rather similar, 

 though having the terminal spine of the outer ramus shorter. Last pair of legs 

 in female of enormous size, foliaceous, wholly obtecting the ovisac below. 



Remarl-s. The type of this new genus is the Thalestris mysis of Glaus, 

 a form which in some characters, and more particularly in the enormous deve- 

 lopment of the last pair of legs in the female, differs conspicuously from the other 

 Thalcstr'ulce, so that it ought more properly to be generically separated. We do 

 not ;at, present know any other form . that can be associated with it in the 

 same genus. 



