Vi have vel seet, at baade Ryg- og Bugkarret afgive 
Grene til Tarmen, Mesenteriet og til Æggestokken; men 
vi have ikke kunnet iagttage nogen Forbindelse imellem 
dem, og langtfra den netformige Karudbredning paa Tar- 
men, som Schmarda angiver at være tilstede hos Bonellia 
viridis. Å 
Der er hos Hamingia vistnok et afsluttet Kredslob ; 
men det er et Spørgsmaal, om dette ikke er dobbelt, saa- 
ledes nemlig, at den Gren af Ryg- og Bugkarret, Fig. 14, 
i, e, der fra den forreste store udbredte Karforgrening,, 
Fig. 14, g, lober langs Tarmens Sider til bag imod de 
sidste Cireumvolutioner, — om ikke disse Kar paa en lignende 
Maade udbrede og forene sig som ved den store Karfor- 
grening; er dette Tilfældet, saa er der et andet Kredslob, 
‘der jo er meget længere end det første. Men, hvilket af 
disse Kar, der virker som Arterie eller Vene, det lader sig 
vanskelig afgjøre Kan det antages, at det flotterende, 
muskuløse Legeme virker som et Hjerte, kan dette be- 
tragtes som et Centralorgan, da forekommer det os, at 
Bugkarret, med hvilket Hjertet staar saagodtsom i umiddel- 
bar Forbindelse, maa repræsentere det arterielle System, og 
følgelig Rygkarret Venesystemet. Dette synes yderligere at 
bekræftes derved, at Bugkarret, der er tykkere, har fastere 
muskuløse Vægge, end Rygkarret. 
Sammenligner man nu Circulationsorganerne hos vort 
Dyr med Bonelliens, saa viser det sig, at de afvige noget, 
hvilket ogsaa var at vente, alene af den Grund, at Hamin- 
gia ingen Snabel har; men Fællesskabet er ikke destomin- 
dre temmelig iginefaldende. Hos Bonellien er den sæk- 
_formige Udvidning af Bugkarret, der flotterer i den mid- 
terste Del af Kropshulheden, udtydet som muligens et pul- 
serende Centralorgan (Hjerte, Lacaze-Duthiers), og forsaa- 
vidt kan det ansees som et Analogon til det særegne Organ 
hos Hamingia, som vi have fundet flotterende i den forreste 
Ende af Kropshulheden, og som staar i Forbindelse med 
Bugkarret. Men omtrent paa det Sted, hvor Lacaze-Du- 
thiers har fundet den sækformige Udvidning af Bugkarret, 
der findes hos Hamingia den særegne Karforgrening, der 
danner Foreningen imellem Ryg- og Bugkar, hvilken ikke 
kan betragtes som nogen Centraldel, men snarere som et 
peripherisk Afsnit af Circulationen. 
Nervesystemet. 
Hos Gephyreerne ialmindelighed er Nervesystemet 
temmelig let tilgjængeligt, og anderledes er det heller ikke 
hos vor nye Slægt. ; 
Naar Tarmrøret er borttaget eller skudt til Side, saa 
fremtræder tydeligt Centralnervestrængen, der langs Midten 
af Bugfladen strækker sig fra Munden til Anus, Fig. 16, a. 
Den har en hvid glindsende Farve, er bundet til Bugmesen- 
teriet, og er beklædt paa sm indre i Kropshulheden frem- 
ragende Flade af Peritoneum. Den ligger altsaa imellem 
dette og Skraamuskellaget. 
29 
Branches proceeding from the dorsal and ventral ves- 
sels to the intestine, the mesentery, and the ovarium, we 
have observed, but have failed to detect any connexion 
‘whatever between them; we certainly did not observe the 
reticulating vascular expansion on the intestine alleged by 
Schmarda to occur in Bonellia viridis. 
Hanungia is’ unquestionably furnished with a true 
circulatory system; but the question arises, whether that 
system be not bifold, inasmuch as the branches of the dor- 
sal and ventral vessels, fig. 14, 2, e, which, issuing from 
the greatly expanded anterior vascular ramification, fig. 14, 
g, protend backwards along the sides of the intestine to 
the last cireumvolutions, may possibly in turn expand and 
unite, precisely as do the vessels at the great vascular 
ramification. Now, assuming this to be the case, a new 
circulation will commence, taking another and much longer 
course. But which of the said vessels conveys venous, and 
which arterial blood, is indeed difficult to decide. If, how- 
ever, the floating muscular body be assumed to perform the 
function of a heart — be regarded as a central organ, the 
ventral vessel, with which it directly communicates, might, 
we think, with good reason be held to represent the arte- 
rial system, and the dorsal vessel the venous. And this 
view would seem to derive additional support from the 
fact of the ventral vessel, which is thicker, having more com- 
pact and muscular walls than the dorsal. 
On comparing the circulatory organs in Hanungia 
with those in Bonellia, they are certainly found to differ 
somewhat, which was indeed to be expected, if for no other 
reason, because of the former not having a proboscis; but 
their mutual resemblance is nevertheless striking. The sac- 
like expansion of the ventral vessel floating in Bonellia in 
the nfiddle of the perivisceral cavity, has been held to re- 
present, possibly, a pulsating central organ (heart, Lacaze- 
Duthiers), and in “that sense it may be regarded as the 
analogue of the organ in Hamingia found floating at the 
anterior extremity of the perivisceral cavity, and which is 
connected with the ventral vessel. Now, about in the place 
where Lacaze-Duthiers observed the sac-like expansion of 
the ventral vessel, occurs in Hamingia the vascular rami- 
fication, connecting together the dorsal and ventral vessels, 
— which can hardly be a central part, but should rather 
bé regarded as a peripheral section of the circulatory system. 
Nervous System. 
In the Gephyree, the nervous system is as a rule 
easily accessible, — an assertion which also holds good of 
our new genus. 
On removing or pushing aside the intestinal canal, 
the central nervous chord — of a lustrous white — is di- 
stinetly visible, protending along the middle of the ventral 
surface from mouth to anus, fig. 16, a. It is webbed to 
the ventral mesentery, and invested on its inner surface, 
which projects into the perivisceral cavity, with peritoneal 
membrane. It extends accordingly between the peritoneum 
and the oblique muscular layer. 
