fjernet og nermet til Mundaabningen og bidrager , 
derved til Fodens Optagelse. Af de 2 Grene er den 
indre ganske kort, cylindrisk og forsynet paa Spid- 
sen med 4 cilierede Borster. Den ydre Gren-er der- 
imod af betydelig Storrelse, omtrent saa lang som 
Skaftet og temmelig tyk, dog gradvis afsmalnende 
mod Enden. Den er meget boielig og viser en An- 
tydning til en tet Leddeling, idet Kanterne er fint 
crenulerede, Langs ad dens indre Side findes en 
Rad af 15—16 sterke, cilierede Svommeborster, 
hvoraf 2 udgaar fra selve Spidsen. — Overleeben er 
meget stor og fremspringende, dannende en oval, i 
en stump Spids endende og i Flugt med Hovedets 
undre Flade gaaende Klap, der ganske dekker 
Mundaabningen nedad. — Kindbakkerne er synlige 
til: hver Side af Overleben som 2 convexe Frem- 
spring; men deres Tyggedele synes endnu ikke at 
vere udviklet. Derimod har enhver Kindbakke paa 
den ydre Side et temmelig stort fodformigt Vedheng 
af aflang oval Form og forsynet med ialt 8 cilierede 
Borster, hvoraf 3 udgaar fra Spidsen, 3 fra en bred 
Lap af den bagre Rand og 2 fra en noget mindre 
Lap mellem denne og Spidsen. To Par smaa knude- 
formige Fremspring umiddelbart bag Kindbakkerne 
antyder Anlegget til de 2 Par Kjever. Af Bran- 
chialfodder er der Anleg til 7 Par, successivt afta- 
gende i Storrelse bagtil. De har alle Formen af 
simple Tvervulster, uden Spor af Borster. Hale- 
enden gaar ud i 2 smaa tilspidsede Lappe, enhver 
endende med en enkelt liden simpel Borste. I det indre 
af Legemet sees tydeligt den med orangefarvet Ind- 
hold fyldte Tarmkanal, der fortil danner to simple 
tilrundede Blindsekke. Larven beveger sig meget 
raskt om i Vandet ved rythmiske Slag af 2det Par 
Folere, som i dette Stadium er dens eneste Loko- 
motionsorganer. 
Det Fig. 16 afbildede Larvestadium er allerede 
adskilligt videre udviklet. Legemet er sterkere 
forlenget og viser en begyndende Sondring i de 3 
Kropsafsnit. Hovedet er dog endnu meget kort og 
nesten tvert afkuttet fortil. De sammensatte Oine 
har nu begyndt. at udvikle sig som to convexe Frem- 
spring ved Basis af Iste Par Folere; I deres indre 
er der afsat.en,ringe Mengde redt Pigment, og der 
er en syag Antydning til Synselementer. De 2 Par 
Folere og Munddelene forholder sig i alt vesentligt 
som hos det. foregaaende Stadium. Derimod er der 
indtraadt en kjendelig Udvikling af de bag Mund- 
delene folgende Lemmer, De i forrige Stadium fore- 
kommende 7 Par simple Tvervulster, der’ repreesen- 
terede Anlegget til Branchialfodderne, har nu for- 
detmeste sondret sig fra Kropssiderne og rager tyde- 
ligt. frem i Form af buede Plader, der er svagt ind- 
54 
bristles. During the movements of the oars, these 
projections are alternately brought near to and 
withdrawn from the oral aperture thereby assisting 
in the admission of food. The inner of the two 
rami is quite short, cylindrical, and furnished at the 
point with 4 ciliated bristles. The outer ramus, on 
the other hand, is of considerable size, about as 
long as the scape, and tolerably chick, though ta- 
pering towards the extremity. It is very flexible, 
and shows an indication of close articulation, the 
margins being finely crenulated. Along its inner 
side, there is a row of 15 or 16 strong, ciliated, 
natatory bristles, two of which issue from the very 
point. The labrum is very large and prominent, 
forming an oval, blunt-pointed flap extending back- 
wards as an immediate continuation of the inferior 
surface of the head, and quite covering the oral 
aperture below. The mandibles are visible on each 
side of the labrum.in the form of 2 convex projec- 
tions, but their masticatory part appears to be still 
undeveloped. Each mandible has, however, on the 
outer side, a rather large, oblong oval leg-like. 
appendage furnished with 8 ciliated bristles, 3 of 
which issue from the point, 3 from a broad lobe of 
the hind. margin, and 2 from a somewhat smaller 
lobe between the hind margin and the point. Two 
pairs of small knob-like projections immediately be-. 
hind the mandibles indicate the 2 incipient pairs of 
maxille. There are indications of 6 pairs of bran- 
chial legs, successively decreasing in size posteri- 
orly. They all have the form of simple transverse 
prominences without a trace of bristles. The end 
of the tail divides into 2 small pointed lobes, each 
terminating in a single, small, simple bristle. Within 
the body may be plainly seen the intestinal canal 
with its orange-coloured contents, forming in front 
2 simple, rounded ceca. The larva moves about 
rapidly in the water with rythmical strokes of the _ 
second pair of antenne, which, in this stage, are its 
only organs of. locomotion. 
The larval stage represented i in fig. 16 is already 
considerably more. developed. The body is more 
elongated, and shows an. incipient, division into the 
3 sections of the body. ‘The head is. still, however, 
very short and almost. abruptly cut off in front. 
The compound eyes have now begun to develop \in 
the form of 2 convex projections at;the base of. the 
first pair of antenne.- Inside them there is.a small 
quantity of red pigment, and there is a faint indi- 
cation of visual elements. The two pairs of antenne 
and the oral parts are essentially in the same con- 
dition as in thé foregoing stadium. On the other 
hand there is a perceptible development of the limbs 
behind the oral parts. The 7 pairs of simple trans- 
verse prominences in the previous stadium, which 
represented the incipient branchial legs, have now 
for the most part separated themselves from the 
