95 



afi'un(letl(! Kndeled er meget reducerede i Aiital. Epi- 

 poditeii er overmaade liden og rudimentær, hvorimod 

 Exopoditen er forholdsvis vel iidviklet, naaende nied 

 sin ventrale Lap langt ud over Endopoditen. Den 

 ei' kantet med omtrent 23 Borster af noget ulige 

 Længde. Meget lignende, skjondt endnn noget sim- 

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

 Exemplarer, saaledes som dette er beskrevet og af- 

 bildet af Prof. Lilljeborg. 



Legemets Farve er hus fnldvoxne Exemplarer 

 mere eller mindre tydelig olivengron, gaaende paa 

 Bugsiden og paa Fodderne over til gulrødt. Selve 

 Skallen er lyst hornfarvet og temmelig gjennem- 

 sigtig, dog meget constant med Dorsalkanten af en 

 ret ioinefaldende nua'k graasort Farve. 



Iiidrc Organer. 



1'aa Grand af denne Forms store (TJennemsigtig- 

 hed, vil den indre (Organisation ret vel kanne stu- 

 deres, navnlig paa levende Exemplarei', tildels ogsaa 

 paa vel ])reserverede Spiritusexemplarer, udeu at 

 iiogen Dissection strengt tåget er fornoden. Kun 

 hvor det gjælder en mere detailleret (histologisk) 

 Undersogelse af Organerne, vil det være nyttigt at 

 skride til en Sonderlemmelse af Dyret. 



]\[ed den sædvanlige Indleirings- og Suitmetliode 

 kommer man ikke synderlig vidt, og denne i vor 

 Tid i saa stor Fdstrækning anvendte Undersogelses- 

 methode synes idethele at være lidet anvendelig, 

 liviir (let gjælder Krebsdyr. 



Fordoielsesapparat. — Tarmen strækker sig som 

 et nogenlunihi jevnt tykt Hor gjennem hele Dyrets 

 Legeme, og skinner meget tydeligt igjennem Tnte- 

 gnmenterne ved dens sædvanligvis niorke Contenta 

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

 kort, stærkt muskuløs Endetarm, senn udmnnder paa 

 Halens Spids, mellem Haleklorne. 1 Xakkesegmentet 

 gjor Tarmen en jdudselig, næsten vinkelformig Boi- 

 ning nedad, i Overensstemmelse med i.iegemets stærke 

 Krumning paa dette Sted. Tai'mens Indhold er i 

 denne forreste Del sædvanligvis lysere, oi'angefarvet 

 eller blegt gulagtigt. S]iis(>roret er ganskt> kort og 

 passerer fra ^lundaabningen lige fnrtil, ti\or det 

 munder i Tarmens ibrreste Ende nu'd en i dens 

 Lumen l'rt'nis]iringend(? nog(>t udvidet Del (se Fig. 'J, 

 oes). 1 I'lU'liindelse med Tarmen staar et temmelig 

 v(duminost og comiiliceret kjertelagtigt Organ (Fig. 

 2, o, /), der udfylder en stor Dtd af Hovedets indre 

 Hub', og aabenbart svarer til den hos Lcpidurits 

 ligeledes i Hovedet beliggende Lever. Ligesom hos 

 Lepidnrus, bestaar Organet af 2 .symetriske Halv- 



from the others. It is very small, and its endoi)o- 

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

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

 as also on the short rounded terminal joint, are 

 greatly reduced in number. The epipodite is excee- 

 ding! v small aTid rudimentary, whereas the exo])o- 

 dite is comparatively well develo])ed, reaching far 

 out over the endo])odite with its ventral lobe. It 

 is edged with about 23 bristles of somewhat uneipial 

 length. The structure of the 24th pair found in 

 very large specimens, though rather more simple, 

 is very similar, as described aiul Hgured !)\- I'rof. 

 Lilljel)org. 



The colour of tlie l)ody in full-grown specimens 

 i.s more or less distinctly olive-green, mei-ging 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 consjiicuously dark 

 grey colour. 



Iiilornal Organs. 



On account of tlie great transparency of this 

 form, its internal organisation nuiy be very easily 

 stiidied, especially in living specimens, to a cei'tain 

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

 out the necessity of dissection. Only when a more 

 minute (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 infornuition is to be gained, and this mode 

 of investigation, now so widely employed, seems, 

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

 ( 'rustaceans. 



Digestive System. — The intestine runs, in the 

 form of a tube of fairly even thickness, througii the 

 whole body of the aninml, and is very distinctly 

 seen through th(> integuments by reason of its gene- 

 rally dark contents (see PI. XV, tig. 1). It termi- 

 nates in the tail in a short, vei'v muscular rectum, 

 which opens out at the ))oint of the tail, l)etween 

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

 stine makes a sudden, almost angular bend down- 

 wards, following the sharp curve of the bod}- at 

 that i)lace. Tlie contents of the intestine in this 

 foremost part are generally lighter, t)f an orange 

 or pale yellow hue. The (esophagus is ([uite short 

 ' and passes from the oral aperture straight for- 

 wards, where it opens into the anterior end of tlie 

 intestine b}' a somewhat expanded part jirojecting 

 into its lumen (see tig. il, oes). In connection with 

 the intestine, tliere is a rather V(duniiiious and 

 complicated glandular organ (tigs. 2, 3, /) occupying 

 a great pai't of the inner cavity of the head, and 

 evidently answering to tlie liver in Lepidurus. whicii 



