95 



afnmdede Endeled er meget reducerede i Antal. Epi- 

 poditen er overmaade liden og rudimentær, hvorimod 

 Exopoditen er forholdsvis vel udviklet, naaende med 

 sin ventrale Lap langt ud over Endopoditen. Den 

 er kantet med omtrent 23 Børster af noget ulige 

 Længde. Meget lignende, skjondt endmi noget sim- 

 plere, er Bygningen af det 24de Par hos meget store 

 Exemplarer, saaledes som dette er beskrevet og af- 

 hildet af Prof. Lillieborg. 



Ltegemets Farve er hos fuldvoxne Exemplarer 

 mere eller mindre tydelig olivengron, gaaende paa 

 Bugsiden og paa Fodderne over til gulrodt. Selve 

 Skallen er lyst hornf arvet og temmelig gjennem- 

 sigtig, dog meget constant med Dorsalkanten af en 

 ret ioinefaldende mork graasort Farve. 



Indre Organer. 



Paa Grund af denne Forms store Gjennemsigtig- 

 hed, vil den indre Organisation ret vel kunne stu- 

 deres, navnlig paa levende Exemplarer, tildels ogsaa 

 paa vel ])reserverede Spiritusexemplarer, tiden at 

 nogen Dissection strengt tåget er fornøden. Kun 

 hvor det gjælder en mere detailleret (histologisk) 

 Undersogelse af Organerne, vil det være nj'ttigt at 

 .skride til en Sonderlemmelse af Dyret. 



Med den sædvanlige Indleirings- og Snitmethode 

 kommer man ikke synderlig vidt, og denne i vor 

 Tid i saa stor Udstrækning anvendte Undersogelses- 

 methode synes idethele at være lidet anvendelig, 

 hvor det gjælder Krebsdyr. 



Fordøielsesapparat. — Tarmen strækker sig som 

 et nogenlunde jevnt tykt Ror gjennem hele Dyrets 

 Legeme, og skinner meget tydeligt igjennem Inte- 

 gumenterne ved dens sædvanligvis morke Contenta 

 (se Tab. XV, Fig. 1). Den ender i Halen med en 

 kort, stærkt muskulos Endetarm, som ixdmunder paa 

 Halens Spids, mellem Haleklorne. I Xakkesegmentet 

 gjor Tarmen en pludselig, næsten vinkelformig Bei- 

 ning nedad, i Overensstemmelse med Legemets stærke 

 Krumning paa dette Sted. Tarmens Lidhold er i 

 denne forreste Del sædvanligvis lysere, orangefarvet 

 eller blegt gvilagtigt. Spiserøret er ganske kort og 

 passerer fra Mundaabningen lige fortil, hvor det 

 munder i Tarmens forreste Ende med en i dens 

 Lumen fremspringende noget udvidet Del (se Fig. 9, 

 oes). I Forbindelse med Tarmen staar et temmelig 

 voluminøst og compliceret kjertelagtigt Organ (Fig. 

 2, 3, /), der ixdfylder en stor Del af Hovedets indre 

 Hule, og aabenbart svarer til den hos Lepiclurus 

 ligeledes i Hovedet beliggende Lever. Ligesom hos 

 Lejiidurus, be.staar Organet af 2 symetriske Halv- 



from the others. It is very small, and its endopo- 

 dite is quite short, with only 3 lobes inside in addi- 

 tion to the coxal lobe. The bristles on these lobes, 

 as also on the short rounded terminal joint, are 

 greatly reduced in number. The epipodite is excee- 

 dingly small and rudimentary, whereas the exopo- 

 dite is comparatively well developed, reaching far 

 out over the endo]iodite with its ventral lobe. It 

 is edged with about 23 bristles of somewhat unequal 

 length. The structure of the 24th pair found in 

 very large specimens, though rather more simple, 

 is very similar, as described and figured by Prof. 

 Lilljeborg. 



The colour of the body in full-grown specimens 

 is more or less distinctly olive-green, merging into 

 yellowish red on the ventral side and on the legs. 

 The shell itself is of a light horn-colour, and toler- 

 ably transparent, though the dorsal margin is 

 almost invariably of a very conspicuously dark 

 grey colour. 



Internal Organs. 



On account of the great transparency of this 

 form, its internal organisation may be very easily 

 studied, especially in living specimens, to a certain 

 extent too, in well-preserved spirit specimens, with- 

 out the necessity of dissection. Only when a more 

 mimite (histological) investigation of the organs is 

 to be made, will it be useful to resort to a dismem- 

 bering of the animal. 



By the ordinary imbedding and section method, 

 not much information is to be gained, and this mode 

 of investigation, now so widely employed, seems, 

 on the whole, to be of very little tise as regards 

 Crustaceans. 



Digestive System. — The intestine runs, in the 

 form of a tulje of fairly even thickness, through the 

 whole body of the animal, and is very distinctly 

 seen through the integuments by reason of its gene- 

 rally dark contents (see PL XV, fig. 1). It termi- 

 nates in the tail in a short, very muscular rectum, 

 which opens oat at the point of the tail, between 

 the caudal claws. In the cervical segment, the inte- 

 stine makes a sudden, almost angular bend down- 

 wards, following tlie sharp curve of the body at 

 that place. The contents of the intestine in this 

 foremost part are generally lighter, of an orange 

 or pale yellow hue. The tesophagus is quite short 

 and passes from the oral aperture straight for- 

 wards, where it opens into the anterior end of the 

 intestine by a somewhat ex[)auded part projecting 

 into its lumen (see fig. 9, oes). In connection with 

 the intestine, there is a rather voluminous and 

 complicated glandular organ (figs. 2, 3, J) occupying 

 a great part of the inner cavity of the head, and 

 evidently answering to the liver in Lepidur us, vååch. 



