128 



traadformig, nogel kortere end Skaftel og sammensal af 

 circa 11 Led. 



Munddelene kunde ikke nøiere undersøges paa det 

 eneste foreliggende Exemplar. 



Iste Fodpar (Fig. 28) er betydelig kortere end de 

 øvrige og uddannet til et Slags Griberedskaber, skjøndt af 

 mindre kraftig Bygning end Ims den typiske Art. Basal- 

 leddet er meget small og næsten san langt som alle de 

 øvrige tilsammen. 4de Led er noget, skjøndt ikke megel 

 opsvulmet og i den indre Kant forsynet med :; stive Bør- 

 ster. Sidste Led er meget bevægeligt forbundet med delte 

 og kan slaaes ind mod samme; det ender med en stærk, 

 tydeligt 2-leddet Klo. 



De øvrige Fodpar er alle af ens Udseende. ægte 

 Gangfødder og at' en sa>rdeles spinkel Bygning. De til- 

 tager noget i Længde forfra bagtil og viser sig ordnede i 

 2 Sæt. idet de 3 forreste er adskilte fra de 3 bagerste ved 

 et meget betydelig Mellemrum, der indtages af det ovenfor 

 omtalte mediane Kropsafsnit. 



Halevedhængene (se Fig. 29) er meget smaa og synes 

 kun at beståa af et enkelt konisk Led. der ved Spidsen 

 har nogle fine Børster. 



Dyrets Farve er ensformig skidden graalig, omtrent 

 som det Mudder, hvori det lever. 



Lamgden af det undersøgte Individ er kun 4.20""". 



Forekomst og Udbredning. Et enkelt Exemplar af 

 denne distincte Art optoges i Bundskraben under Expedi- 

 tionens 2det Togt i Havet Vest af Lofoten fra et Dyb af 

 778 Favne. 



Om Artens Udbredning kan selvfølgeligt intet med 

 Bstemthed anføres; men da den ovennævnte Station tilhører 

 den kolde Area. er der al Rimelighed for. at den er en 

 ægte arktisk oa- for de nordlige Have eiendommelig Form. 



Fam. 2. Munnopsidæ, Lilljeborg. 



d8opoda remigantia, (i. O. Sårs) 



Bemærkninger. De til denne Familie horende Iso- 

 poilcr udnuerker sia i hoi Grad ved den mærkværdige Byg- 

 ning af de :; bagerste Fodpar, der er meget ulige de øvrige 

 saavel i Form som Function, idet de er uddannede til 

 mægtige Svømmeredskaber, hvormed Dyret kan, ofte med 

 stoi- Fart. bevæge sig frit om i Våndet i baglæn ds Retning. 

 Denne Oharacter er i Virkeligheden saa eiendommelig og 

 nlig alt. hvad vi hidtil kjendte, at jeg i Begyndslsen blev 

 forledet til berpaa at grunde en ganske egen Isopodetribus, 



simple-cylindric. The flagellum is filiform, somewhat shorter 

 than the pedunele. and composed of about 14 articulations. 



The oral appendages could not be submitted to close 

 examination in the sole specimen obtained. 



The Ist pair of legs (fig. 28) are considerably shorter 

 than the rest. and developed asa kind of prehensile organs, 

 though less powerful in structure than in the typical species. 

 The basal joint is exceédingly slender, and well-nigh as 

 long as all the others tåken together. The 4th joint is 

 somewhat, though not mueh, swollen, and furnished along 

 the iiiner margin with 3 stiff bristles. The last joint is 

 very movably connected with the latter, and admits of 

 being bent in towards it; this last joint terminates in a 

 strong. distinctly bi-articulate claw. 



The remaining pairs of legs are all uniform in ap- 

 pearance, being true pereiopoda. and exceédingly slender 

 in structure. They increase somewhat in length posteriorly, 

 and are arranged in 2 series, the 3 anterior being separated 

 from the 3 posterior pairs by a very considerable interspace, 

 occupied by the aforesaid medial section of the body. 



The caudal appendages (see fig. 29) are very small, 

 and would appear to consist of hut one conical joint, fur- 

 nished at the extremity with a few delicate bristles. 



The colour of the animal is a uniform dirty grev. 

 much the same as that of the mud in which it lives. 



Length of the specimen examined only 4.20""". 



Oceurrence and Distribution. — A single specimen 

 of this distinctly characterized species was brought up in 



the dr 



eaee on 



the 



.'ml cruise o 



f the Expedition, in the open 



sea west of Lofoten, from a depth of 778 fathoms. 



Respecting the distribution of the species. nothing can 

 of course he stated with eertainty; hut the Station at which 

 the specimen was tåken being in the cold area. there is 

 every reason to regard the animal as a true Arctic form. 

 peculiar to the fauna of the Northern Seas. 



Fam. 2. Munnopsidæ, Lilljeborg. 



dsopoda remigantia, (i. 0. S;ir^i 



Remarks. — The Isopoda belonging to this family 

 are verv prominently distinguished by the remarkable struc- 

 ture of the 3 posterior pairs of legs, differing most essentially 

 as they do alike in form and function, being developed to 

 powerful natatory organs, by means of which the animal, 

 often with great rapidity. can move through the water in a 

 backward direction. This character is indeed so peculiar 

 and unlike anything hitherto obsei*ved, that at first I felt 

 disposed to establish from it a distinct tribe of Isopods, 



