24 



Resultater, hvortil jeg er kommet, stemmer idethele 

 temmelig vel overens med hvad Claus her har med- 

 delt. Paa Tab. V fremstiller Fig. 1 en Hun seet 

 fra Siden og stærkt foi-storret, med de forskjellige 

 Organer indtegnede i samme og anlagte med for- 

 skjellige Farver. Fig. 2 fremstiller et Tværsnit af 

 Legemet omtrent over Midten af Truncus; de indre 

 Organer er anlagte med samme Farve som paa 

 Hovedfiguren. 



Tarmtractus- 



Spiserøret er meget kort og stiger fra Mund- 

 aabningen lodret i Veiret, forbindende sig under en 

 næsten ret "Vinkel med den forreste, i Hovedet lig- 

 gende Del af Tarmen. Dette forreste Afsnit af 

 Tarmtractus er for.synet med et temmelig compli- 

 ceret Chitinskelet (Tab. V, Fig. 3, 4) og danner saa- 

 ledes et Slags Tyggemave, noget lignende den hos 

 Amphipoderne forekommende. Paa Chitinskelettet 

 kan adskilles 3 Hoveddele, en forreste, en midterste 

 og en bagerste Del. Den forreste Del er noget 

 affladet og indeholder 2 fortil divergerende Lister, 

 besatte med en dobbelt Rad af fine, tæt sammen- 

 trængte Cliitinpigge. Lige ved Indgangen til Spise- 

 røret tindes desuden ventralt 2 parvise Forlioininger, 

 besatte med indadrettede Borster. Den midterste 

 Del er temmelig stærkt opsvulmet og bagtil skraat 

 afskaaret, dannende her en næsten klokkeformig 

 Udvidning, hvorfra rager frem et Par tæt haarede 

 Flige. Det er her at de til Tarmen horende Lever- 

 sække forener sig for at udmunde i Tyggemavens 

 Lumen. Den bagerste Del, endelig, danner en lang 

 skedeformig, og i de frie Kanter med fine Børster 

 besat tynd Flig, der kun indtager Dorsalsiden af 

 Tarmen og med sin i en fin Spids udtrukne Ende 

 rækker langt ind i selve Truncus. Tarmen danner 

 forøvrigt et simpelt cjdindriskt, med stærke Ring- 

 muskler forsynet Rør, der strækker sig igjennem 

 hele Midtkroppen, Bagkroppen og Mesteparten af 

 Halen. Ved Enden af næstsidste Halesegment for- 

 binder den sig med en kort. stærkt muskuløs Ende- 

 tarm, der aabner sig nedenunder Basis af Halegre- 

 nene. Af Leversække findes ikke mindre end 4 Par, 

 alle særdeles tynde og saa fast forbundne med Tar- 

 men med fedtholdigt Bindevæv, at de yderst vanske- 

 ligt lader sig isolere fra samme. Det forreste af 

 disse Par er meget korte og rettede fortil over 

 Tyggemaven, medens de 3 øvrige Par følger Tarmen 

 bagud og ender omtrent ved Begyndelsen af Halen. 

 Paa Tværsnit (Fig. 2) viser disse sidste (cd, cv) sig 

 grupperede næsten i Form af en Rosette omkring 

 og tæt ind mod Tarmen, med et noget større Mel- 

 lemrum mellem det dorsale Par. 



nified figures of male aud female, presented as 

 transparent objects. The results at which I have 

 arrived agree, upon the whole, pretty well with 

 what Clans has here stated. Plate V, fig. 1 repre- 

 sents a female viewed laterally and greatly magni- 

 fied, with the various organs drawn in the repre- 

 sentation and coloured with diff'erent colours. Fig. 2 

 represents a transversal section of the body across 

 nearly the middle of the truncus ; the internal organs 

 are coloured with the same colours as in the chief 

 figure. 



The intestinal tract. 



The oesophagus is very short and rises per- 

 pendicularly from the oral aperture, connecting 

 itself at almost a right angle with the foremost 

 part of the intestine situated in the head. That 

 foremost section of the intestinal tract is fur- 

 nished with a pretty complicated chitinous skeleton 

 (PI. 4, fig. 3. 4) and forms thus a kind of mastica- 

 tory stomach, somewhat like what is present in the 

 Amphipods. Three chief parts maj' be distinguished 

 in the chitinous skeleton, a front one. a medial one, 

 and a back one. The front portion is somewhat 

 flattened and contains 2 fillets which diverge to 

 the front and are beset with a double series of fine, 

 closely crowded chitinous spikes. Exactl}^ at the 

 mouth of the oesophagus there are further found, 

 ventrally, 2 prominences in pairs, beset with bristles 

 directed inwards. The medial part is pretty greatly 

 swollen out and obliquely truncated behind, forming 

 here a nearly bell-shaped dilation, from which a 

 pair of densely hirsute flaps project. It is here 

 that the liver-sacs pertaining to the intestine 

 unite, in order to debouch into the cavity of the 

 masticatory stomach. The posterior part finally 

 forms a long sheath-like thin flap which is, on its 

 free edges, beset with fine bristles, and only occupies 

 the dorsal side of the intestine; and which, with its 

 extremity drawn out to a fine point, extends far 

 into the truncus itself. The intestine forms, other- 

 wise, a plain cylindrical tube furnished with strong 

 ring-muscles, which extends itself through the entire 

 mesosome, the metasome, and the greater part 

 of the urosome. At the extremity of the pen- 

 ultimate caudal segment, it connects itself to a short, 

 strongly muscular rectum which opens below the 

 base of the caudal rami. Of liver-sacs there are 

 no less than 4 pairs found, all of them particularly 

 slender, and so firmly connected to the intestine b^^ 

 fatty connective-tissue that it is extremely difficult 

 to isolate them from it. The foremost pair of these 

 sacs is very short and directed forwards above 

 the masticatory stomach, while the 3 other pairs 

 follow the intestine backwards and terminate at 

 about the beginning of the urosome. In trans- 

 versal sections (fig. 2) these last show themselves 



