Sl 



Ai' Munddolpiip ev (se Fift-. 21; Ovcrlii'lieii (I.) 

 og Kinclbakkenie (M) let at dliscrvci-o, di;- s\-ni's i 

 alt vipsciitlig't at li^no .«amme hos det \-(ixiio Dyr. 

 Af iiogeii >"\fMiidilmlar|ial|ie er der intetsonilielst 

 S])or at se, skjondt den ganske, sikkert liar existerot 

 paa et tidligere Stadinni. Unilerlælien og 1\ jæverne 

 har jeg ikke kunnet noii'i'e undersoge. 



Af Fodderne er de til ^[idtkroiipen liorende i*ar 

 allerede taalelig vel udvii<lede, niecl alle sine Hoved- 

 dele t_ydelige, hvorimod de liagre 1'ar Idiver i lioi 

 (rrad rudimentære, t'orestii](>nde tilsidst meget smaa. 

 utydeligt indskaarne Skiver uden enkver l^orste- 

 hesætning (Fig. 26). 



For.ste Fodpar (Fig. 22) viser i Henseende til 

 Enditerne endnn ingen.somlielst l''(irskj(d fra de nær- 

 mest toigende I'ar (Fig. 2o), og den y(lei'ste eller 

 5te Endit, der lio.s det voxne J)yr er ganske rudi- 

 mentær, er her ligesaa vel lulviklet som ]iaa de fol- 

 gende Fodder. Derinn.id er i"]xo]]oditen kjendelig 

 mindre og kun forsynet mecl S iJandliorster, ine<li''is 

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

 saadanne Ilte Fodpar (Fig. 24:' er endnn kun lidet 

 iidviklet og viser intet Tegn til nogen Ægka])sel. 

 Exopoditen er paatværs oval og forsynet med en 

 Rad af 9 forhoklsvis korte Kandhorster. l']])ipoditen 

 er meget liden, knudeformig, og Enditerne afstum- 

 pede i Enden. Paa de folgende Par (Fig. 25) hliver, 

 som ovenfor nævnt, alle disse Dele eiidmere rudi- 

 menla're, og tilsidst .Fig. 26 ; er der neppe mere 

 end ulietyihdige Sjior af dem tilbage. 



.\f indre Organer skinner Tarmen meget tyde- 

 Hgt igji'imem Integumentei-ne (se Tal». XI, Fig. 4) 

 og er ialmindelighed fyldt med (irangefai-vede Con- 

 tenta. Fortil udsender den 2 korte lilindsa'kke 

 (Tab. \J11, Fig. 21. 1), der hver klover sig i 2 (irene, 

 hvoraf igjen enhver er svagt tvelappet i Fnden. 

 Dette er B(>g\-ndelsen til den hos det voxne D\t 

 saa volnmiiHJse og comjiliicreile Lever. 



I']t noget senere Stadium er fremstillet '1'ali. XI, 

 Fig. 5. Legemet har nu en r.a>ngde af omtrent 4 

 mm. og er endnu halvt gjennemsigtigt, med et svagt 

 gronagtigt Skjær og gulrod gjennemskinnende Tai'in. 

 JJygskjoldet er nu forholdsvis noget storre, men 

 endnu temmelig liadt, og Kroppen har strakt sig 

 noget mere i T^ængde. Forovrigt stemmer dette 

 Stadium meget na'r med det foregaaende, og 2det 

 Par Folei-e fungerer fi-emdeles som Svommeredska- 

 her, skjondt do er noget redueerede i Størrelse, me- 

 dens Fodderne synes mere udviklede. 



n — ti. 0. Sars : Fauna Sorveijix. 



extremity with ;5 ciliated bristles of unequal 

 length. 



Of the oral parts (see tig. 21). the labrnm 1 1^) 

 and the nnmdibles (Jf) are easy to oliserve, and seem 

 in exery essential ])artieular to lesemble those parts 

 in the full-grown animal There is no traie what- 

 ever of a mandibular ])ali), though it nuist certainly 

 ha\'e existed at an e;irlier stage. The posterior lip 

 and the maxilhe L have not been able to examine 

 closelv. 



The ])airs of legs b(donging to the meso.some 

 are already t(derabi\- well developed, all their priu- 

 ci])al ]iarts being distiin-t, whereas the posterior 

 ])uirs become extremidv I'udimentary. appearing at 

 last like very sm.ill, indistinctly indented lamellæ, 

 entirel\' without bristles (tig. 2l)). 



As regards the endites. the first jiair of legs 

 (tig. 22i presents as \et no ditference whatever from 

 the pairs immediately tollowing (tig. 23', and the 

 outermost or 5tli endite. which in the full-grown 

 animal is (piite rudimentary, is here just as well 

 developed as in the succeeding legs. On the other 

 hai'd the exo|)odite is jterceptibly smaller, and fur- 

 msned with t)nly S nmrgimil bristles, wliile that of 

 the 2nd ])air (tig. 23) lias no less than 14 such 

 bristles. The 11th jiair of legs ifig. 24) is as vet 

 only slightly developed, and shows no sign of anv 

 egg-capsule. The exopodite is transversely oval, and 

 furnishefl with a I'ow of 9 comjiaratively short mar- 

 ginal liristles. The ejiipodite is luidiform and verv 

 snmll, and the endites are truncated at the extre- 

 mity. In the suci'eeding ])airs i^^tig. 25\ ail these 

 parts l)econu^ as stated above, more and more rudi- 

 mentary, until at last (tig. 2t)'l there is hardly more 

 than a slight vestige of them lett. 



Of the internal organs, the intestine shows verv 

 distinctly through the integuments se Pl.XU. tig. 4), 

 its contents generally being of an orange colour. 

 It sends out in front 2 short ca'ca (PI. XIII, tig. 

 21, 1), wliicli each divide into 2 branches, eaidi of 

 which is in its tuin sliglitl\" bi lobed at the extre- 

 mity. This is the commencement of the verv volu- 

 minous and complicated lix'cr found in the full-grown 

 animal. 



PI. XI. tig. 5 repi'esents a rather later stage. 

 The bod\' has now a length of about 4 mm. and is 

 still semi-transpai'ent, with a faint greenish tinge, 

 and the yellowish-red intestine showing through. 

 The cara])ace is now comjiaratively ratiier lai'ger, 

 though still somewhat Hat, and the trunk has 

 somewhat increa.sed in length. In other respects 

 this stage agrees very closely with the preceding 

 one. and the 2nd pair of antennæ still ofticiate as 

 swimming im]denients, though they are somewhat 

 reduced in .size, while the legs a]ipear to lie more 

 develo])ed. 



