a 
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stillede Fortsatser, hvoraf den midterste forestiller 
Rostrum. 
Forekomst og Leyevis. 
Det eneste Sted her i Landet, hvor denne Phyllo- 
pode hidtil er observeret, er i Ostfinmarken ved 
Matsjok, en Biflod til Tana, hvor Prof. Collett fandt 
den i Sommeren 1885. Da jeg nogle Aar senere, i 
1888, bereiste Finmarken, undlod jeg ikke at besoge 
denne Lokalitet, og var ogsaa saa heldig at finde 
den her i Slutningen af August meget almindeligt 
i en grund, med talrige Vandplanter bevoxet Groft. 
Alle Exemplarer var da fuldt udviklede og syntes 
at have opnaaet sit Maximum af Storrelse. Skjondt 
jeg noie undersogte alle Damme og Grofter i Om- 
egnen, var det mig dog ikke muligt at finde noget 
Spor af den andetsteds end netop i den omtalte 
Groft, der saaledes maa have frembudt serlig gun- 
stige Forhold til dette Dyrs Trivsel. 1 Lobet af 
nogle faa Dage indsamledes her et betydeligt Antal 
Exemplarer, ligesom Observationer anstilledes over 
det levende Dyr i mine Excursionsglasse. Dyrets 
Bevegelser er temmelig klodsede og lidet udhol- 
dende, bestaaende i et noget ujevnt og ligesom rul- 
lende Lob gjennem Vandet, hvorunder snart Ryg, 
snart Bug vendes opad. Under Beveegelsen er Ho- 
vedet helt fremstrakt af Skallen, saa at Aarerne fuldt 
kan virke, og Valvlerne er herunder vidt aabne neden- 
til. Jeg kunde ikke observere, at Dyret nogensinde, 
som Tilfeeldet er med Limnadia, feestede sig til de i 
Vandet veerende Gjenstande. Naar Bevegelsen op- 
horte, sank Dyret hurtigt til Bunden, og laa her 
ofte i lengere Tid ubevegeligt paa Siden, for saa 
igjen at foretage en kort Udflugt i Vandet. Hanner 
og Hunner forekom nesten i samme Antal og saaes 
ofte i Copulation, hvorunder Hannen med sine Gribe- 
fodder med stor Kraft omfatter Kanterne af Hun- 
nens Valvler nedentil. Selve Parringsakten fik jeg 
dog ikke observere. At domme efter Kindbakkernes 
Beveebning, synes Dyrets Nering at vere mere 
-animalsk end Tilfeeldet er med de ovrige bivalve 
Phyllopoder, og bestaar rimeligvis for en stor Del 
af mindre Entomostraceer. 
Udbredning. — Denne Phyllopode blev forst 
opdaget af O. F. Miiller i Damme ner Kjobenhavn, 
og er ogsaa senere her gjenfunden. Foruden i Dan- 
mark er den observeret ved Danzig af Liévin, ved 
Dorpat af Grube, i Lillerusland ved Charkow og i 
Ungarn ved Pest, endelig ogsaa i Sibirien. I sin 
Udbredning synes den saaledes idethele, i Modseet- 
ning til Limnadia, at vere en ostlig Form, og det 
er aabenbart ad den Vei, nordenom den _ botniske 
Bugt, at den har udbredt sig til vort Land. 
processes, the middle one of which represents the 
rostrum. 
Occurrence and Habits. 
The only place in this country (Norway) where 
this Phyllopod has hitherto been observed is in Kast 
Finmark, near the Matsjok, a tributary of the Tana, 
where Prof. Collett found it in the summer of 1885. 
When some years later, in 1888, I travelled through 
Finmark, I did not fail to visit this locality, and 
had also the good fortune to find it there at the 
end of August, very plentiful, in a shallow ditch 
where numerous aquatic plants grew. All the spe- 
cimens were then fully developed, and seemed to 
have attained their maximum size. Although I care- 
fully examined all the ponds and ditches in the 
neighbourhood, I did not succeed in discovering any 
trace of it anywhere except in the said ditch, which 
must thus have offered conditions especially favo- 
rable to this animal’s well-being. Ig the course of 
a few days, a considerable number of specimens 
- were collected here, and observations made of the 
living animal by watching them in my collecting- 
jars. The animal’s movements are rather awkward, 
and not very persevering, consisting in a some- 
what uneven and, as it were, rolling course through 
the water, sometimes with the dorsal, sometimes 
with the ventral side uppermost. During the 
movement the head is stretched right out of the 
shell, so that the oars can have their full effect, 
the valves meanwhile being wide open below. 
I never observed the animal attaching itself to 
objects in the water, as is the case with Lim- 
nadia. When the motion ceased, it sank quickly 
to the bottom, and often lay there a long time on 
its side, motionless, then again making a short ex- 
cursion through the water. Males and females are 
found in almost equal numbers; and are often seen 
in copulation, during which the male, with its pre- 
hensile legs, embraces with great power the lower 
edges of the female’s valves. The act of copulation 
itself, however, I have not witnessed. Judging 
from the armature of the mandibles, the animal’s 
food appears to be more animal than is the case 
with the other bi-valve Phyllopoda, and probably 
consists to a great extent of smaller Entomostraca. 
Distribution. — This Phyllopod was first disco- 
vered by O. F. Miiller, in ponds near Copenhagen, 
and has also been found there again subsequently. 
Besides in Denmark, it has been observed by Liévin 
at Danzig, by Grube at Dorpat, at Charkow in 
Little Russia, at Pesth in Hungary, and lastly in 
Siberia. It therefore appears, in opposition to Lim- 
nadia, to be, in its distribution, an eastern form, and 
it is evidently by way of the north of the Gulf of 
Bothnia, that it has spread to our land (Norway). 
17 — G. O, Sars: Fauna Norvegie. 
