23 



men skiller sig forøvrigt ikke s^nulerligt i sin 

 Bygning. 



De 2 Par rudimentære Bagkropslemmer (Fig. 6 

 og 7) er ligeledes noget storre end hos Hunnen, og 

 sidste Par (Fig. 7) har her et tj-deligt afsat lidet 

 Rodled, ligesom Iste Par. I sin Form og Bevæbning 

 stemmer iøvrigt liegge Par temmelig noie overens 

 med samme hos Hunnen. 



Halegrenene udmærker sig (se Tab. I, Fig. 3) 

 ved en i Forhold til samme hos Hunnen meget paa- 

 faldende Lærigde, idet de endog er saa lange som 

 de 5 bagre Bagkropssegmenter tilsammen, eller næ- 

 sten af Legemets halve Længde. I>e er (Tab. IV, 

 Fig. 8), som hos Hunnen i hver Kant bevæbnede 

 med en Rad af korte Torner, hvoraf dog de i Yder- 

 kanten her er meget talrigere og finere end de i 

 Inderkanten. Desuden tindes, som hos Hunnen, langs 

 den indre Kant en Rad af temmelig lange og tynde 

 Fjær horster. 



Farven er i levende Tilstand gjennemgaaende 

 blegere end hus Hunnen og Legemet halvt gjennem- 

 sigtigt. 



Indre Organer. 



Undersøgelsen af den indre Organisation er hos 

 nærværende Dyreform forbunden med ganske sær- 

 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 Grrund af det complicerede System af 

 Muskler, som omgiver og tildels fylder den i og for 

 sig meget trange Kropshule. Hertil kommer endnu 

 et meget stærkt udviklet, og med talrige Fedtkiigler 

 fyldt Binde væv, som omspænder de forskjellige Or- 

 ganer og kun vanskeligt lader sig skille fra samme. 

 Heller ikke Snitniethoden 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 udvælge enkelte 

 ualmindelig gjennemsigtige og helst ganske unge 

 Lidivider og undersoge disse directe under Mikro- 

 .skopet i levende Tilstand. Ved at combinere disse 

 Undersøgelser med hvad jeg har kunnet fremstille 

 ved Dissection, har jeg endelig efter meget Besvær 

 troet at faa nogenlunde Rede paa den indre Orga- 

 nisation hos denne mærkelige Dyreform. Forst 

 etterat disse Undersøgelser forlængst var afsluttede, 

 erholdt jeg Prof. Claus's fortjenstfulde Arbeide: 

 «Untei'suchungen zur Erforschung der genealogischen 

 Grundlage des Crustaceen-Systeni», hvori den indre 

 Organisation hos Nebalia i Korthed omtales, med 

 Vedføielse af stærkt forstørrede Figurer af Han og 

 Hun, fremstillede som transparente Objecter. De 



than in the female (see Pl. I, fig. 3), but do not other- 

 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 the}- 

 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 tlie female, along the inner edge, a series of 

 pretty long and thin. plumose setæ. 



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 (juite 

 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 stronglj^ 

 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 aftbrded 

 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 usualh^ trans- 

 parent, and preferably quite young, individuals, and 

 bv investigating these in the live state directly under 

 the microscope. By combining these investigations 

 with what I have been able to ]n'esent 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 -Untersueliungen zur Erforschung 

 der genealogischen Grundlage des Cnistaceen S3'- 

 stem» in which the internal organization of Nebalia 

 is shortly mentioned, and illustrated liy greatly mag- 



