Sectio I. Anostraca. 
(Negne Phyllopoder). 
Syn: Phyllopoda pisciformia. 
Character. Legemet forlenget, meget blodt og 
beieligt, mere eller mindre ormformigt, uden Spor 
af noget Rygskjold eller Skal. Legemets Segmen- 
tering temmelig uniform, dog med tydelig Adskillelse 
i Hoved, Midtkrop og Hale. Qinene tydeligt stilkede 
og beveegelige, af en lignende Bygning som hos Ne- 
balia. Forste Par Folere meget smaa, traadformige; 
2det Par hos Hunnen mere eller mindre rudimentere, 
fligformige, hos Hannen omdannede til kloformige 
Griberedskaber. Kindbakkerne med stump riflet 
Tyggeflade, uden tydeligeTender. Branchialfodderne 
uden Coxallap, men med 1 eller 2 Deekblade ved 
Basis paa den ydre Side, alle af noget ner ens Byg- 
ning, udpreget respiratoriske, men samtidigt ogsaa 
locomotoriske. Halen uden Lemmer, dens forreste 
Segmenter delvis sammenvoxne og givende Udspring 
for de ydre Kjonsvedheng: hos Hunnen en enkelt, 
mere eller mindre sewkformig Agbeholder med ter- 
minal Aabning, hos Hannen 2 fuldsteendig skilte og 
meget smaa Copulationsredskaber. Udviklingen en 
compliceret Metamorphose begyndende med et frit 
Nauplius-Stadium. / 
Bemerkninger. De til denne Afdeling herende 
Phyllopoder er let kjendelige ved sit langstrakte og 
blede, nzsten ormlignende Legeme, ved Mangelen af 
et Rygskjold eller Skal, ved de tydeligt stilkede 
Mine, ved den eiendommelige Bygning af 2det Par 
Folere hos de to Kjon, endelig ved den eiendomme. 
lige Beskaffenhed af de ydre Kjonsvedheng. Man 
kan fordele de hidtil bekjendte Former paa 3 Fa- 
milier: Branchipodide, Thamnocephalide og Polyarte- 
miide. Kun den forste og sidste af disse Familier 
er representerede i Norges Fauna. Den 3die Fa- 
milie er opstillet af Packard for en merkelig nord- 
amerikansk Form, 7'hamnocephalus platywrus Packard,.- 
der, foruden ved de eiendommelige Frontalvedheng, 
udmerker sig i hoi Grad derved, at Halen ender 
med en enkelt bred horizontal Svommeplade. 
39 
Sectio I. Anostraca. 
(Naked Phyllopods). 
Syn: Phyllopoda pisciformia. 
Characters. Body prolonged, very soft. and 
flexible, more or less vermiform, without trace of 
any carapace or shell. The segmentation of the 
body pretty uniform, but with distinct division be- 
tween the head, the mesosome and the tail. Eyes 
distinetly pedunculated and moveable, of similar 
structure to these in Nebalia. First pair of antenne 
very small, filiform. Second pair more or less rudi- 
mentary in the female, flap-shaped; transformed 
in the male to claw-formed prehensile apparatus. 
Mandibles with blunt rifled masticatory surface, with- 
out distinct teeth. Branchial feet without coxal 
lobe, but with one or two covering plates at the 
base on the outer side; all of somewhat uniform 
structure, distinguished respiratory, but at same 
time also locomotive. Tail without appendages; the 
foremost segments partly coalescent and furnishing 
the origin for the outer sexual appendages: in the 
female a single, more or less sac-formed marsupium 
with terminal aperture; in the male 2 completely 
separated and very small copulative appendages. 
The development a complicated metamorphosis, com- 
mencing with a free Nauplius stage. 
Remarks. The Phyllopods belonging to this 
division are easily recognizable by their elongate 
and soft, almost vermiform body, by the absence of 
a carapace or shell, by the distinctly pedunculated 
eyes, by the peculiar structure of the 2nd pair of 
antenne in the two sexes and, finally, by the pe- 
culiar character of the outer sexual appendages. We 
may refer the hitherto known forms to 3 families: 
Branchipodide, Thamnocephalide and Polyartemiide. 
Only the first and last named of these families are 
represented in the fauna of Norway. The 3rd family 
is established by Packard, to include a remarkable 
‘North American form, Thammnocephalus platyurus, 
Packard, which, besides by its peculiar frontal 
appendages, distinguishes itself in a high degree, 
in that the tail terminates in a single, broad hori- 
zontal swimming plate. 
