ur, 



ruiulet Form. med den ovre Kant, livor Valvlerne 

 stoder sammen, uæsten ret og endende 8aavel fortil 

 som bagtil med et tj-deligt fremspringende Hjorne. 

 Ovenfra seet (se Fig. S) viser den sig temmelig 

 buget, idet Breden næsten er lig Hoiden. Til hver 

 Side sees Skalkjertelen med den ximiddelbart foran 

 samme liggende Mnskelarea med stor Tydelighed, 

 og paa (xrnnd af Skallens store Gjennemsigtighed 

 træder ogsaa den af samme bedækkede Del af Lege- 

 met klart og tydeligt frem. Man kan nn paa Lege- 

 met adskille alle de Afsnit, som ovenfor er beskrevet 

 lios det voxne Dyr. Dog er Xakkesegmentet endnu 

 temmelig kort, og Truncus knn lidet længere end 

 det forreste Afsnit af Legemet. Hovedet bar en 

 fra samme bos det voxne Dyr temmelig afvigende 

 Form. Dets ovre Flade er noget nregelmæssigt 

 bvælvet og endmi uden Spor af det cbaracteristiske 

 stilkede Fastbeftningsorgan, som forst senere dan- 

 nes ved en gradvis Afsnoring af en Del af Hovedets 

 Dorsalparti. Pandedelen er endnn knn lidet frem- 

 springende, og melleni den og det stnmpt tilnindede 

 1-vostrnm er der neppe engang den svageste Lidbiigt- 

 ning at se. Af Hovedets Yedbæng er Iste Par Fo- 

 lere lidt mere forlængede end bos Larverne, nåen 

 endnn forholdsvis smaa og nden laterale Lappe. 

 2det Par Folere, eller Aarerne, bar, som ovenfor 

 anfort, tabt baade den bagndboiede Bor.ste ved Enden 

 af Skaftet og den tvedelte basale Fortsats. For- 

 ovrigt stemmer de, saavel bvad Skaftets som Gre- 

 nenes Bygning angaar, temmelig nær overens med 

 samme bos Larvenie, alene med den Forskjel, at 

 der i Yderkanten af den ovre Gren bar ndviklet sig 

 en kort Pig, bvoraf intet Spor var at se bos bine. 

 Overlæben er nn betydelig reduceret i Storrelse og 

 bar antaget det for det voxne Dyr ebararteristiske 

 ITdseende, idet den lange, dolkformige Endedel er 

 svnndet ind til en forholdsvis liden tentakelformig 

 Fortsats. Paa Kindbakkerne er der endnn igjen et 

 Rndiment af Mandibularfodderne i Form af et til 

 deres Yderside fæstet nbetydeligt koniskt Appendix 

 i^den Spor af Leddeling eller Borstebesætning. Bag 

 Kindbakkerne sees de 2 Par Kjæver, som nn, lige- 

 som Kindbakkerne, er i fuld Virksombed med at 

 bearbeide den optagne Xæring. De bos Larven an- 

 lagte (3 Par Branebialfodder er nn functionsmæssigt 

 ndviklede, ndforende sine cbaracteristiske svingende 

 Bevægelser for Eespirationens og Xæringsoptagel- 

 sens Formaal, og bag dem er der endnn Anlæg 

 til 3 eller 4 Par nye Fodder. Haledelen er endnn 

 knn svagt omboiet og Haleklorne nfuldstændigt son- 

 drede fra Haleenden. De bar hver nær Basis en 

 enkelt kort Sidetand, og nmiddelbart ovenfor dem 

 ndgaar fra Halens Dorsalside 2 meget smaa jevn- 

 sides stillede Fremspring, som forestiller det forste 

 Anlæg til de tandede Haleplailer. Ovenfor Hale- 

 borsterne har der endvidere ndviklet sig et enkelt 

 Par af de bos det voxne Dvr ber inrekommende 



valves meet, almost straight, and ending both in 

 front and Ijebiud in a distinctly projecting corner- 

 Seen from above (see fig. 8), it apjiears rather 

 bnlging, its breadth being almost eqnal to its 

 beiglit. On each side is seen the shell-gland very 

 distinctly, with the muicnlar area lying immediately 

 in front of it; and on acconnt of the great trans- 

 parency of the shell, that part of the body which 

 it covers is seen very clearly and distinctly. All 

 the sections of the body described above in the 

 adnlt animal, can now he distingnished. The cervi- 

 cal segment, however, is still rather short, and the 

 trnnk only a little longer than the foremost section 

 of the body. The head has a rather different shape 

 to that in the adnlt animal. Its upper surface is 

 somewhat irregularlj' arched, and still without a 

 trace of tlie characterLstie stalked organ of attach- 

 ment, which is formed, but not until later, by a 

 gradual constriction of a part of the dorsal region 

 of the bead. The frontal region still projects only 

 slightly, and between it and the bluntly rounded 

 rostrum, there is scarcely even the slightest hollow 

 to be seen. Among tlie appendages of the head, 

 the first pair of antennæ is a little more elongated 

 than in tlie larva, but still cumparatively small 

 and without lateral lobes. Tlie 2nd pair of antennæ, 

 or the oars, have, as stated above, lost both the 

 backward-curved bristle at tlie end of the scape and 

 the bifid basal projection. In other respects they 

 agree very closely, as regards the structure of both 

 the scape and the rami, with those limbs in the 

 larva, with the one difference that in the outer 

 margin of tbe up])er ramus a short spike has deve- 

 lojied, of which there was no trace in the larva. 

 The labrum is now considerably reduced in size, 

 and has assumed the appearance characteristic of 

 tbe adult animal, the long, ensiform terminal part 

 liaving sbrnnk into a comparatively small, tenta- 

 cular projection. There is still a rudiment of the 

 mandibular legs left on tbe mandibles in the form 

 of an indistinctly conical appendage, — without a 

 trace of articulation or bristles, — attached to their 

 outer side. Beliind the mandibles are seen the 2 

 pairs of maxillæ, which now, like the mandibles, 

 are in full activity, manipulating tbe food admitted. 

 Tbe (') pairs of lu-ancbial legs commenced in tbe 

 larval stage are now able to perform their function, 

 executing their characteristic swinging movements 

 for the purpose of respiration and the admission of 

 food; and there are the rudiments of 3 or 4 pairs 

 of new legs. Tlie caudal part is stiU only slightly 

 bent down, and the caudal claws impei'fectly marked 

 off from the end of tbe tail. Tbej- each have near 

 the base a single, short, lateral tooth, and imme- 

 diately above tliem, there is.sue from tbe dorsal 

 side of the tail 2 veiy small jnxtajiosed projections, 

 representing the earliest rudiment of the dentated 



