af Hunkjon, sker der en end yderligere Reduktion 
af disse Folere, hvorved de antager det for Hunnen 
characteristiske Udseende af 2 simple triangulere 
Flige. Hos Hannen omformes Ydergrenen til Gribe- 
kloen, og Indergrenen persisterer som det lille knude- 
formige Fremspring ved Enden af Basaldelen, inden- 
denfor Kloens Udspring. 
Forekomst og Levevis. 
Nerverende Phyllopode synes at forekomme 
meget almindelig, i Ost-Finmarken, hvor jeg har 
taget den paa flere Steder i stor Mengde; saaledes 
i et lidet grundt Tjern ved Mehavn, hvor den fand- 
tes sammen med Polyartemia forcipata, i et lignende 
Tjern ved Vardo, og i flere Smaatjern og grunde 
Damme paa Fastlandet Ost af Vardo. Af Prof. 
Lilljeborg er den desuden taget ved Nordkap. I 
Vest-Finmarken har jeg derimod ikke observeret 
den, ligesaalidt som nogetsteds i Nordland. Merke- 
ligt nok optreeder den igjen langt sydligere i Lan- 
det, nemlig paa Dovres Hoeideplateau, hvor jeg har 
taget den meget almindelig i grunde Damme saavel 
ved Kongsvold som ved Jerkin. Denne isolerede 
Forekomst saa langt Syd paa kan kun forklares 
paa den Maade, at nerverende Phyllopode for i 
Tiden, da Klimatet var mere arktiskt, har veeret 
udbredt over hele vort Land, ogsaa i Lavlandet, 
men derpaa, efterhvert som Klimatet forandrede sig, 
har trukket sig tilbage nordpaa og tillige til Hoide- 
plateauerne, hvor de klimatiske Forhold mere lig- 
nede de oprindelige; med andre Ord: den er her Syd 
i Landet at betragte som en saakaldt «relict» Form, 
en Leyning fra den arktiske Fauna, der for i Tiden 
var udbredt over vort hele Land. | 
Da de Smaatjern og Damme, hvori den lever, 
regelmessigt udtorres mod Slutningen af Sommeren, 
og vesentlig kun skylder sin Tilbliven Snesmeltnin- 
gen paa Forsommeren, er denne Forms Levetid kun 
indskreuket til nogle faa Maaneder af Aaret. I 
Lobet af forholdsvis kort Tid har den imidlertid 
gjennemgaaet sin Udvikling, og derefter gaar For- 
plantningen hurtigt for sig. De i Agsekken inde- 
holdte Ag, bliver, som anfort, altid omgivne med en 
meget tyk Skal og er aabenbart alle beregnede paa 
at overvintre, for til den folgende Sommer at ud- 
vikle sig til en ny Generation. Arten er saaledes 
for hvert Aar kun representeret ved en enkelt Ge- 
neration. iggene afsettes i Mudret paa Bunden 
af Dammen, og da denne Afsetning af Ag foregaar 
gjentagne Gange af hvert Hunindivid, vil der snart 
ophobe sig en anseelig Mengde af Aig, der vil sikre 
Artens Tilverelse paa de Steder, der er gunstige 
for dens Trivsel. Det er forst ved Midsommertid, 
| with no bristles whatever. 
If the young one. is 
destined to be of the female sex, a still further re- 
duction of these antenne takes place, whereby they 
assume the appearance, characteristic of the females, 
of 2 simple triangular flaps. In the male the outer 
ramus is transformed into a prehensile claw, while 
the inner ramus becomes the small nodiform pro- 
jection at the end of the basal part, inside the root 
of the claw. 
Occurence and Habits. 
The present Phyllopod seems to occur very ge- 
nerally in East Finmark, where I have found it in 
many places in great numbers, for instance, in a 
little, shallow lake at Mehavn, where it was found 
together with Polyartemia forcipata; in a similar 
lake at Vardo, and in several small lakes and 
shallow ponds on the mainland east of Vardo. It 
has also been found by Prof. Lilljeborg at the North 
Cape. In West Finmark, on the other hand, I have 
not observed it, nor yet anywhere in Nordland. 
Curiously enough, it appears again much farther 
south, namely on the high plateau of the Dovre 
Mountains, where I found it very plentiful in shal- 
low ponds both at Kongsvold and Jerkin. This 
isolated occurrence so far south can only be ac- 
counted for by the supposition that formerly, when 
the climate was more arctic, this Phyllopod was 
distributed over the whole of our land (Norway), 
lowlands as well as highlands, but that, as the cli- 
mate changed, they have withdrawn to the north 
and the high plateaus, where the climatic conditions 
more resemble those originally prevailing; in other 
words, here in the south of the country, it must be 
regarded as a so-called «relict» form, a vestige of 
the arctic fauna which was formerly distributed 
over the whole country. 
As the small lakes and ponds in which it lives 
dry up periodically towards the end of the summer, 
and owe their existence chiefly to the melting of 
the snow in the spring, the life-time of this form 
is limited to only a few months of the year. In 
the course of a comparatively short time, however, 
it has passed through its developmental course, and 
propagation then proceeds rapidly. As already stated, 
the eggs in the ovisac always become surrounded by 
a very thick shell, and are evidently calculated to 
stand the winter, and in the ensuing summer to 
develop into a new generation. The species is thus 
represented every year only by a single generation. 
The eggs are deposited in the mud at the bottom 
of the pond, and as this deposition of eggs is re- 
peated several times by each female, a considerable 
number of eggs is soon amassed, which ensures the 
existence of the species in those places that are fayor- 
able to its well-being. It is not until Midsummer 
