ter. Bag disse 7 Par Lemmer sees endnu 2 Par 
smaa Tveervulster, hvorved disse Lemmers Antal er 
steget til 9 Par. Endnu mangler imidlertid ethvert 
Spor til de 2 sidste Par, som forst senere anlegges 
paa samme Maade som de ovrige. Bagkroppen er 
endnu gauske kort og uleddet. Dens Endelapper 
har sondret sig fra Haleenden og berer nu hver 3 
 borsteformige Vedheng, hvoraf det midterste er be- 
tydelig storre end de 2 ovrige. 
Fig. 17 fremstiller den forreste Del af Legemet 
hos et lidt senere Larvestadium, seet nedenfra og 
noget sterkere forstorret. De sammensatte Mine (0) 
har tiltaget betydelig i Storrelse og viser sig alle- 
rede kort stilkede, med @iengloben vel udviklet. 
iste Par Folere (a') er paa det nermeste uforan- 
drede. 2det Par Folere (a*) synes forholdsvis min- 
dre, idet de er bleven staaende paa samme Udvik- 
lingstrin, medens de fleste ovrige Dele er tiltaget i 
Storrelse. Det samme gjelder ogsaa Mandibular- 
fodderne (p), som i Forhold til selve Kindbakkernes 
Corpus (M) synes meget reducerede. Overleeben (L) 
er fremdeles meget stor og fremragende. De 2 Par 
Kjever er allerede tydeligt udviklede og forsynede 
med en Del Borster. Alle Branchialfodder er nu 
anlagte, men-de 2 bagerste Par endnu kun tilstede 
som ubetydelige Tvervulster. 
Under den videre Udvikling sondrer Anlegget 
til de 2 bagerste Par Branchialfodder sig fra Krops- 
siderne som tydeligt fremragende Lemmer, Halen 
strekker sig i Leengden og bliver, som det ovrige 
Legeme, tydeligt segmenteret, samtidigt med at 
Halepladerne mere tydeligt afgrendser sig og faar 
et storre Antal Borster. 2det Par Folere reduceres 
mere og mere, men beholder dog endnu en Tid lang 
sine Syommeborster og beveges som hos de yngre 
‘Larver. Mandibularfodderne svinder mere og mere 
ind og er tilsidst kun tilstede som rudimentere Ved- 
heng. Larven, som paa dette Stadium har en Lengde 
_ af omtrent 5 mm, staar nu paa Overgangen til at 
 antage den blivende Tilstand. Den er afbildet paa 
2 dette Udviklingstrin Tab. VI, Fig. 5 og 6. Ved den 
— derpaa folgende Hudskiftning er Larvetilstanden 
- forbi, idet det sidste Spor af Mandibularfodderne er 
__ forsvundet og 2det Par Folere har tabt sin Betyd- 
‘oe ‘ning af Lokomotionsorganer. Endnu er der dog paa 
de sidstneeynte Lemmer (se Fig. 7 og 8) en tydelig 
; Adskillelse mellem Skaft og Grene. Den ydre Gren 
ender i en noget bugtet Spids, paa hvilken endnu 
de sidste svage Rester af de oprindelige Svomme- 
A borster sees (Fig. 8); Indergrenen ser ud som et 
-yderst: lidet: knudeformigt Fremspring, uden enhver 
peseenbels ‘Er- og bestemt. til at blive 
j La i Kanterne og delvis forsynede med korte | 
> s 
sides of the body, and project perceptibly in the 
form of curved lamellew, slightly. indented and 
with the edges partially furnished with bristles. 
Behind these 7 pairs of limbs, 2 more pairs of 
small transverse prominences are visible, raising 
their number to 9 pairs. All trace, however, of 
the last 2 pairs is still absent, and it is only 
later that they commence in the same way as the 
others. The hind part of the body is still quite 
short and inarticulated. Its terminal lobes have 
become separated from the caudal end, and now 
each carry 3 setiform appendages, the middle one 
of which is considerably larger than the other two. 
Fig. 17 represents the anterior part of the body 
in a somewhat more advanced larval stage, seen 
from below, and rather strongly magnified. The 
compound eyes (0) have increased considerably in 
size, and already have short peduncles, while the 
eye-ball is well-developed. The Ist pair of antenne 
(a*) are nearly unchanged. The 2nd pair of antenne 
(a?) seem to be comparatively smaller, having re- 
mained at the same developmental stage, while most 
of the other parts have increased in size. The same 
applies to the mandibular legs (p), which, in relation 
to the body of the mandible (M), seem very much 
reduced in size. The labrum (L) is still very large 
and projecting. The two pairs of maxille are al- 
ready perceptibly developed, and furnished with a 
few bristles. All the branchial legs have now ap- 
peared, but the hindmost 2 pairs still only as insig- 
nificant transverse prominences. 
During further development the rudiments of 
the hindmost .2 pairs of branchial legs separate 
themselves from the sides of the body as distinctly 
projecting limbs. The tail is elongated and becomes, 
like the rest of the body, perceptibly articulated, 
while, at the same time, the caudal lamelle are 
more distinctly defined, and havé acquired a larger 
number of bristles. The second pair of antenne be-* 
come more and more reduced, but still for some 
time retain their natatory bristles, and are -moved 
as in the younger larve. The mandibular legs 
dwindle more and more, and at last only appear as 
rudimentary appendages. The larva, which, at this 
stage, has a length of about 5 mm, is on the point 
of entering its permanent condition. It is thus re- 
presented on Pl. VI, figs. 5 and 6. With the en- 
suing exuviation, the larval period is past, the last 
trace of mandibular legs having vanished, and the 
2nd pair of antenne having lost their importance 
as organs of locomotion. In the last-named limbs 
(see figs. 7 and 8) there is still, however, a distinct 
separation between the scape and the rami. The 
outer ramus ends in a somewhat curved point, upon 
which the last feeble remains of the original nata- 
tory bristles are visible (fig. 8). The inner ramus 
looks like an extremely small nodiform projection, 
