med et Ord selve Alggestokken, der for ham var ukjendt. 
Det er neppe nogen Tvivl underkastet, at de Orga- 
ner Max Miiller kalder Æggestokke ere fuldstændig homo- 
loge med de af os beskrevne Æggebeholdere hos Hamingia, 
ihvorvel de i Formen afvige noget; men lægger man Mærke 
til, at Miller omtaler en lille Fremstaaenhed, paa hvilken 
han tror at have fundet en Aabning, kan dette neppe være 
noget andet, eud den hos Hamingia og Bonellia paa Uterus 
værende Tragt, der tjener til at opsamle og lede de 1 
Kropshulheden frit svømmende Æg ind i Æggebeholderen. 
Hos Thalassema foregaar, efter Semper's og Spengel's 
Tagttagelser, Ægdannelsen paa en aldeles lignende Maade, 
som hos Bonellia. 
Vi mene saaledes at have bevist, at den af os. opstil- 
lede nye Slegt staar i et nært Forhold til Thalassema og 
Bonellia; men ser man hen til, at der hos vor Slægt, baade 
i de ydre Karakterer og i Anatomien er størst Fællesskab 
med Bonellia, turde det være et Spørgsmaal om den ikke 
i phylogenetisk Henseende staar i den inderligste Rapport 
til denne... Hamingia bærer virkelig Spor af en fordums 
Snabel, der tør være forsvunden, og ved hvis Forsvinden 
naturligvis saavel Circulations- som Nervesystemet maatte 
undergaa nogen Forandring, hvilket jo viser sig at være 
Tilfældet, idet den kredsformige Dannelse af de neeynte 
Systemer, hvilken foregaar i Snabelen hos Bonellia, træder 
op hos Hamingia under Form af-en Nervering og Blodkar- 
ring, der omgive den forreste Del af Spiserøret. 
Kan det antages, at Bonellien oprindelig har havt to 
Uteri, hvilket kan være rimeligt nok, da den ene har et 
meget usymetrisk Leie, og kommer dertil, at Lacaze-Du- 
thiers har fundet hos et Exemplar 2 Uteri, som han forre- 
sten angiver som ganske exceptionelt, — saa er det ikke 
noget ukjendt, at det tabte Orgau atter optræder i en høiere 
Afstamning, og vi ere tilbøielige til at antage, at Hamingia 
staar noget høiere i Organisationsrækken end Bonellia. 
Hamingia arctica ever paa sandholdig Lerbund, be- 
væger sig temmelig meget ved Krumninger 1 forskjellige 
Retninger, uden at gjøre nogen synderlig Fremgang. 
Farven er mørk græsgrøn, naar Dyret er sammen- 
trukket, men bliver lysere med enkelte mørkere Partier, 
naar det er udspændt, og da bliver Huden saa gjennem- 
sigtig, at en Del af Tarmkanalen kan sees. Mundskiven 
med Mundlæberne ere næsten hvide, spillende lidt i det 
Gule, ligeledes de lange cylindriske, krumbøiede Papiller 
paa Bugfladen. 
Kun et Exemplar blev fundet paa Station 290. 
: 
 Slægtskarakter. 
Legemet valseformigt. Munden paa den forreste Ende, 
nærmere Bugfladen. Analaabningen i Centrum af den 
Den norske Nordhavsexpedition. Danielssen og Koren: Gephyrea. 
33 
ingly uteri, though he does not even allude to the true 
ovary, of whose existence indeed he knew nothing. 
Meanwhile, it will hardly admit of doubt, that the 
organs by Max Miiller termed ovaries are strictly homo- 
logous with the uteri, or uterme pouches, in Hamin- 
gia, though slightly different as to form; but calling to 
mind the minute “papilla mentioned by Miiller, and in 
which he believes to have detected an opening, the’ latter 
must assuredly be the funnel-shaped aperture which in 
Hamingia and Bonellia serves for the reception of the ova 
floating in the perivisceral cavity, and to afford them egress 
on their passage into the uterine pouch. 
In Thalassema, according to Semper’s and Spengel's 
observations, the ova are developed precisely as in Bonellia. 
Hence we conceive to have shown, that the genus 
established m this Memoir is closely allied alike to Tha- 
lassema and to Bonellia; but whereas Hamingia, both as 
regards its habitus and anatomical structure, exhibits great- 
est resemblance to Bonellia, it is a question whether, phyl- 
ogenetically too, the new genus will not prove to have most 
intimate relations with that animal. For Hamingia does 
indeed retain traces of a proboscis, once distinguishing the 
genus Bonellia, and the loss of which must naturally to 
some extent have modified the characteristics of the circula- 
tory and nervous systems. And this is found to be the 
case; for the semi-circular formation of the said systems 
in the proboscis of Bonellia, occurs in Hamingia as a 
nervous ring and an annulary vascular blood-vessel, which 
represent together the anterior portion. of the cesophagus. 
Now, assuming Bonellia to have had originally two 
uterine pouches, — for the single uterus with which it is 
now furnished is anything but symmetrical in position, — 
and calling to mind, too, that Lacaze-Duthiers records his 
having once found two uteri in a specimen of this genus 
(quite an exceptional case, however, in his opinion) — sci- 
ence is not without imstances in point showing the organ 
thus lost to have developed again in a congener of higher 
extraction; and we are indeed disposed to regard Hamingia 
as ranking above Bonellia in the scale of organisation. 
Hamingia arctica affeets a bottom of sabulous clay, 
moves about a good deal in disrupted curyes, without how- 
ever making much progress. 
Colour, when the animal is contracted, a dark grassy- 
green, but lighter, with a few darkish patches, when it 
blows itself out; the skin is then so translucent, that part 
of the intestinal canal may be seen through -it. Buccal 
disk and lips almost white, with a faint tinge of. yellow; 
likewise the long, cylindrical, arcuate papillæ of the ven- 
tral surface. 
One example only, at Station 290. 
å Generic Character. 
Body cylindrical; mouth at the anterior extremity, 
nearest the ventral surface. Anal opening in the centre 
oO 
