ved Spidsen og i Inderkanten. Ingen median Hale- 

 plade tilstede. Den indre Organisation nærmest lig 

 samme hos Ampliipoderne. Æggene gjennemgaar 

 sin Udvikling indenfor Rygsbjoldets Valvler, mel- 

 lem Forkroppens Branchialfodder. Ungens Udvikling 

 directe, iiden Metamorphose. 



Bemærkninger. — Indtil for ganske nylig kjendte 

 man af nærværende Familie kun en eneste Slægt 

 nemlig Slægten Nehalia. Under Challenger-Expedi- 

 tionen blev imidlertid opdaget 2 herhen horende 

 Former, der begge danner Typer for særskilte Slæg- 

 ter og nærmere er omtalte i min Bearbeidelse af de 

 under denne Expedition indsamlede Phyllocarider. 

 Begge disse Slægter iidmærker sig ved den eien- 

 dommelige Udvikling af Branchialfodderne. Medens 

 disse hos den ene Slægt, Paranebalia Claus, er, 

 navnlig hos Hunnen, ualmindelig stærkt forlængede, 

 saa at de i visse Henseender selv minder om For- 

 kropslemmerne hos visse Schizopoder (Euphausiidæ), 

 er de hos den anden Slægt, Xehaliojjsis G. 0. Sårs, 

 reducerede til meget smaa, utj^deligt lappede, mem- 

 branøse Plader, der viser endnu mindre Lighed med 

 sædvanlige Fødder end hos de mest tj^piske Branchio- 

 poder. Den 3die Slægt, Nebalia, staar i Henseende 

 til Branchialfoddernes Udvikling paa en Maade midt 

 imellem hine 2 Slægter og repræsenterer saaledes 

 det for Familien tj'piske Forhold. I Henseende til 

 den ovrige Organisation synes der ikke at være 

 synderlig stor Forskjel mellem de 3 Slægter, omend 

 man ogsaa her forefinder Characterer af utvivlsom 

 generisk Betydning. Alene den typiske Slægt, Ne- 

 halia, er representeret i vor Fauna. 



Gen. Nebalia, Leach. 



Slægtscharacter. — Rygskjoldet stærkt sammen- 

 trykt, bagtil i Midten dybt indbugtet. Sidelappene 

 af betydelig Størrelse, bredt afrundede og dækkende 

 næsten hele det forreste Afsnit af Bagkroppen. 

 Pandepladen smalt tungeformig, med eller uden ter- 

 minal Spina. Truncus forholdsvis kort. Bagkroppen 

 betydelig længere end Forkroppen, jevnt afsmalnende 

 bagtil, uden skarp Begrændsning mellem det forreste 

 og bagerste Afsnit. Oinene mere eller mindre ud- 

 viklede, hvert ved Basis dækket af en tilspidset, 

 skjælformig Plade De øvre Følere kortere end de 

 nedre, Skaftet 4-leddet, med en stærk knæformig 

 Bøining mellem 2det og SdieLed; sidste Led noget 

 tidvidet mod Enden og lebende fortil ud i et kort, 



powerful bifurcate swimming legs; the 2 succeeding 

 pairs rudimentary. The 2 last segments without 

 any ventral appendages. Caudal rami simple, linear 

 or lamellar, closel}'^ beset with bristles at the tip 

 and on the inner edge. No medial caudal plate. 

 Internal organization approximating closest to that 

 of the Amphipods. The ova undergo their develop- 

 ment inside the valves of the carapace, between the 

 branchial legs of the anterior division of the body. 

 The development of the young direct, without any 

 metamorphosis. 



Remarks. — Until quite lately we knew only 

 a single genus of this family viz., the genus Nebalia. 

 There were collected on the Challenger Expedition, 

 however, 2 forms pertaining to the familj', which 

 both form types of special genera, and are more 

 particular^ described in my Report of the Phyllo- 

 carida collected by that Expedition. Both of those 

 genera distinguish themselves by the peculiar devel- 

 opment of the branchial legs. Whilst these in the 

 one genus, Paranebalia, Claiis, are, especially in the 

 female, unusually greatly prolonged, so that in 

 certain respects they even remind one of the appen- 

 dages of the anterior division of the body in certain 

 Schizopods (Euphausiidæ), they are in the other 

 genus, Nebaliopsis, G. 0. Sars, reduced to very small, 

 indistinctlj- lobate membranous plates that show 

 still less resemblance to ordinarj- legs than in the 

 most typical Branchiopods. The 3rd genus, Nebalia, 

 stands, in regard to the development of the branchial 

 legs, in a manner intermediate between those two 

 genera, and thus represents the relation that is 

 typical of the family. In regard to the rest of the 

 organization there does not appear to be an)' mate- 

 rial difference between the 3 genera, although we, 

 here, also find characteristics of indubitable generic 

 importance. Only the typical genus, Nebalia, is 

 represented in the Norwegian Fauna. 



Gen. Nebalia, Leach. 



Generic characters. — Carapace greatly com- 

 pressed, deeply insinuated in the middle posteri- 

 ori}-, the lateral lobes of considerable size, broadly 

 rounded and covering nearly the entire front section 

 of the posterior division of the body. Frontal plate 

 narrow linguiform, with or without terminal spina. 

 Truncus relatively short. The posterior division of 

 the body considerablj^ longer than the anterior 

 division, tapering evenly backwards, without sharp 

 demarcation between the foremost and hindmost 

 sections. Eyes more or less developed, each covered 

 at the base by an acuminate squamiform plate. 

 Superior antennæ shorter than the inferior ones ; 

 peduncle 4-jointed with a strong geniculate bend 



