81 



Af Munddelene er (se Fig. 21) Overlæben (L) 

 og Kiiulbakkerne (M) let at observere, og synes i 

 alt A-æsentligt at ligne samme hos det voxne Dyr. 

 Af nogen Mandibnlarpalpe er der intetsomhelst 

 Spor at se, skjondt den ganske sikkert liar existeret 

 paa et tidligere Stadinm. Underlæben og Kjæverne 

 har jeg ikke kunnet noiere nndersøge. 



Af Fodderne er de til Midtkroppen horende Par 

 allerede taalelig vel ndviklede, med alle sine Hoved- 

 dele tydelige, hvorimod de bagre Par bliver i hoi 

 Grad rudimentære, forestillende tilsidst meget smaa, 

 utydeligt indskaarne Skiver uden enhver Børste- 

 besætning (Fig. 26). 



Forste Fodpar (Fig. 22) viser i Henseende til 

 Enditerne endnu ingensorahelst Forskjel fra de nær- 

 mest folgende Par (Fig. 23), og den yderste eller 

 5te Endit, der hos det voxne Dyr er ganske rudi- 

 mentær, er her ligesaa vel udviklet som paa de fol- 

 gende Fodder. Derimod er Exopoditen kj endelig 

 mindre og kun forsynet med 8 Randborster, medens 

 den paa 2det Par (Fig. 23) har ikke mindre end 14 

 saadanne. Ilte Fodpar (Fig. 24) er endnu kun lidet 

 udviklet og viser intet Tegn til nogen Ægkapsel. 

 Exopoditen er paatværs oval og forsynet med en 

 Rad af 9 forholdsvis korte Randborster. Epipoditen 

 er meget liden, knudeformig, og Enditerne afstum- 

 jjede i Enden. Paa de folgende Par (Fig. 2.5) bliver, 

 som ovenfor nævnt, alle disse Dele endmere rudi- 

 mentære, og tilsidst (Fig. 26) er der neppe mere 

 end ubetydelige Spor af dem tilbage. 



Af indre Organer skinner Tarmen meget tyde- 

 ligt igjennem Integumenterne (se Tal). XI, Fig. 4) 

 og er ialmindelighed fyldt med orangefarvede Con- 

 tenta. Fortil udsender den 2 korte Blindsække 

 (Tab. XIII, Fig. 21, 1), der hver klover sig i 2 Grene, 

 hvoraf igjen enhver er svagt tvelappet i Enden. 

 Dette er Begj'ndelsen til den hos det voxne Dyr 

 saa voluminose og complieerede Lever. 



Et noget senere Stadium er fremstillet Tab. XI, 

 Fig. 5. Legemet har nu en Længde af omtrent 4 

 mm. og er endnu halvt gjennemsigtigt, med et svagt 

 gronagtigt Skjær og gulrod gjennemskinn ende Tarm. 

 Rygskjoldet er nu forholdsvis noget storre, men 

 endnu temmelig fladt, og Kroppen har strakt sig 

 noget mere i Længde. Forovrigt stemmer dette 

 Stadium meget nær med det foregaaende, og 2det 

 Par Følere fungerer fremdeles som Svommeredska- 

 ber, .skjondt de er noget reducerede i Størrelse, me- 

 dens Fodderne synes mere udviklede. 



11 — G. 0. Sårs : Fauna Norvegiæ. 



extremity with 3 ciliated bristles of uneipial 

 length. 



Of the oral parts (see fig. 21), the labruin (L) 

 and the mandibles (M) are easj' to observe, and seem 

 in every essential particular to resemble those parts 

 in the full-grown animal. There is no trace what- 

 ever of a mandibula}- palp, though it must certainly 

 have existed at an earlier stage. The posterior lip 

 and tlie maxillæ 1 have not been able to examine 

 closeh'. 



The pairs of legs lielonging to the mesosome 

 are already tolerably well developed, all their prin- 

 cipal parts being distinct, whereas the posterior 

 pairs become extremely rudimentary, appearing at 

 last like very small, indistinctly indented lamellæ, 

 entirely without bristles (fig. 26). 



As regards the endites, the first pair of legs 

 (fig. 22) presents as yet no difl:'erence whatever from 

 the pairs immediately following (fig. 23), and the 

 outermost or 5th endite, which in the full-grown 

 animal is quite rudimentary, is here just as well 

 developed as in the succeeding legs. On the other 

 hand the exopodite is perceptibly smaller, and fur- 

 nished with only 8 marginal bristles, while that of 

 the 2nd pair (fig. 23) has no less than 14 su(di 

 bristles. The 11th pair of legs (fig. 24) is as yet 

 only slightly developed, and shows no sign of any 

 egg-capsule. The exopodite is transversely oval, and 

 furnished with a row of 9 comparatively short mar- 

 ginal liristles. The epipodite is nodiform and very 

 small, and the endites are truncated at the extre- 

 mity. In the succeeding pairs (fig. 25), all these 

 parts become, as stated altove, more and more rudi- 

 mentary, until at last (fig. 26) there is hardly more 

 than a slight vestige of them left. 



Of the internal organs, the intestine shows very 

 distinctly through the integuments (sePl.XII, fig. 4), 

 its contents generally being of an orange colour. 

 It sends out in front 2 short cæca (Pl. XIII, fig. 

 21, 1), which each divide into 2 branches, each of 

 which is in its turn slightly bi-lobed at the extre- 

 mity. This is the connnencement of the very volu- 

 minous and complicated liver found in the full-grown 

 animal. 



PI. XI, fig. 5 represents a rather later stage. 

 The l)ody has now a length of about 4 mm. and is 

 still semi-transparent, with a faint greenish tinge, 

 and the yellowish-red intestine showing through. 

 The carapace is now comparatively rather larger, 

 though still somewhat flat, and the trunk has 

 somewhat increased in length. In other respects 

 this stage agrees very closely with the preceding 

 one, and the 2nd pair of antennæ still officiate as 

 swimming implements, though they are somewhat 

 reduced in size, while the legs ajipear to be more 

 developed. 



