23 
men skiller sig forevrigt ikke synderligt i sin | than in the female (see PI. I, fig. 3), but do not other- 
Bygning. 
‘De 2 Par rudimentere Bagkropslemmer (Fig. 6 
og 7) er ligeledes noget storre end hos Hunnen, og 
sidste Par (Fig. 7) har her et tydeligt afsat lidet 
Rodled, ligesom 1ste Par. I sin Form og Bevebning 
stemmer iovrigt begge Par temmelig noie overens 
med samme hos Hunnen. 
Halegrenene udmerker sig (se Tab. I, Fig. 3) 
ved en i Forhold til samme hos Hunnen meget paa- 
‘faldende Leengde, idet de endog er saa lange som 
de 5 bagre Bagkropssegmenter tilsammen, eller ne- 
sten af Legemets halve Lengde. De er (Tab. IV, 
Fig. 8), som hos Hunnen i hver Kant bevebnede 
med en Rad af korte Torner, hvoraf dog de i Yder- 
kanten her er meget talrigere og finere end de i 
Inderkanten. Desuden findes, som hos Hunnen, langs 
den indre Kant en Rad af temmelig lange og tynde - 
Fjzrborster. 
Farven er i levende Tilstand gjennemgaaende 
blegere end hos Hunnen og Legemet halvt gjennem- 
sigtigt. 
Indre Organer. 
Undersogelsen af den indre Organisation er hos 
nerverende Dyreform forbunden med ganske ser- 
lige Vanskeligheder. Dyret er ialmindelighed ikke 
gjennemsigtigt nok til at at man kan umiddelbart stu- 
dere denne paa det levende Dyr, og ved Dissection 
af opbevarede Exemplarer kommer man ikke meget 
langt, paa Grund af det complicerede System af 
Muskler, som omgiver og tildels fylder den i og for 
sig meget trange Kropshule. Hertil kommer endnu 
et meget sterkt udviklet, og med talrige Fedtkugler 
fyldt Bindeveev, som omspender de forskjellige Or- 
ganer og kun vanskeligt lader sig skille fra samme. 
Heller ikke Snitmethoden har givet mig fuldt ud 
tilfredsstillende Resultater. Bedst har jeg kunnet 
faa undersogt den indre Bygning i sin Helhed ved 
af et stort Antal Exemplarer at udvelge enkelte 
ualmindelig gjennemsigtige og helst’ ganske unge 
_ Individer og undersoge disse directe under Mikro- 
skopet i levende Tilstand. Ved at combinere disse 
Undersogelser med hvad jeg har kunnet fremstille 
ved Dissection, har jeg endelig efter meget Besveer 
troet at faa nogenlunde Rede. paa den indre Orga- 
nisation hos denne merkelige Dyreform. Forst 
efterat disse Undersogelser forlengst var afsluttede, 
erholdt jeg Prof. Claus’s fortjenstfulde Arbeide: 
«Untersuchungen zur Erforschung der genealogischen 
Grundlage des Crustaceen-System», hvori den indre 
Organisation hos Nebalia i Korthed omtales, med 
Vedfoielse af steerkt forstorrede Figurer af Han og 
Hun, fremstillede som transparente Objecter. De 
wise distinguish themselves particularly in their 
structure. 
The 2 pairs of rudimentary, posterior append- 
ages of the body (figs. 6 and 7) are likewise some- 
what larger than in the female, and the last pair 
(fig. 7) have here a distinctly defined, small basal 
joint like the 1st pair. In their shape and armature 
both pairs correspond otherwise pretty exactly with 
the same organs in the female. 
The caudal rami distinguish themselves (see 
Pl. I, fig. 3) by a very striking length in relation 
to the length of the same in the female, as they 
are even as long as the 5 backmost segments of the 
posterior body taken together, or nearly half the 
length of the body. They are (PI. IV, fig. 8), as in 
the female, armed on each edge with a series of 
short spines, of which, however, those on the outer 
edge are here much more numerous and finer than 
those of the inner edge. There are found, besides, 
as in the female, along the inner edge, a series of 
pretty long and thin plumose sete. 
The colour, in the live state, is, pervadingly, 
paler than in the female, and the body is semi- 
transparent. 
Internal organs. 
The investigations of the internal organization 
is in the present animal form attended with quite 
special difficulties. The animal is generally insuffi- 
ciently transparent to enable us to study it directly 
in the living state; and on dissection of preserved 
specimens we make no great progress on account of 
the complicated muscular system which surrounds 
and partly fills the, in itself very narrow, body- 
cavity. To that is added still, a very strongly 
developed, and with fatty globules filled, connective- 
tissue, which encloses the various organs, and per- 
mits itself with difficulty to be separated from 
them. Neither has the sectional method afforded 
me completely satisfactory results. I have been 
enabled to investigate the internal structure in its 
entirety best, by choosing from among a large 
number of specimens some more than usually trans- 
parent, and preferably quite young, individuals, and 
by investigating these in the live state directly under 
the microscope. By combining these investigations 
with what I have been able to present by dissec- 
tion, I have finally after much difficulty, I believe, 
been able to obtain in some measure an elucidation 
of the internal organization of this remarkable ani- 
mal form. First after these investigations had long 
previously been concluded, did I obtain Prof. Claus’s 
admirable work «Untersuchungen zur Erforschung 
der genealogischen Grundlage des Crustaceen Sy- 
stem» in which the internal organization of Nebalia 
is shortly mentioned, and illustrated by greatly mag- 
