114 



Hvad disse Hudlegemers Function betræffer, saa har 

 derom hersket forskj eilige Meninger. Ifølge vore Under- 

 søgelser maa vi med Bestemthed erklære dem for Afson- 

 drings organer. Vi have paa levende Dyr seet Slim i 

 Form af Traadé komme udaf Aabningerne for disse Or- 

 ganers Udførselskanaler, ligesom vi have fundet coagu- 

 leret Slim indeni dem. Hos flere af vore Phascolosoma- 

 Arter findes ogsaa Slim paa Kroppens Overflade, især 

 hos Ph. squamatum, hvis ujævne Hud som Eegel er dæk- 

 ket af et Lag ved Slim sammenbundet Smaasand. Oscar 

 Schmidt 1 ) har angivet, at Aspidosiphon Miilleri afsondrer 

 temmelig meget Slim, der skal spille en Kolle ved Ud- 

 hulingen af de Gange i Kalkstenen, hvori Dyret lever, — 

 ligesaa have vi ofte iagttaget at Bonellia viridis afsondrer 

 Slim, saa Slimsecretioner hos Gephyreerne ikke ere saa 

 særegne endda. 



Hudlegemernes Form og indre Bygning tør blive et 

 godt Hjælpemiddel for Artens Diagnose, naar de først 

 ere tilstrækkelig kj endte hos en Mængde Arter. Vi have 

 ikke havt Materiale nok til at kunne opstille noget Be- 

 stemt i saa Henseende; men skulde det virkelig vise sig 

 saa, hvad vi have en svag Formodning om er Tilfældet, 

 at Hudlegemernes Form og Bygning er forskj ellig hos de 

 forskj eilige Arter, — da vil Bestemmelsen af disse Dyr, 

 der i deres Ydre ofte ere meget vanskelige at adskille, 

 blive betydelig lettet. 



MUSCULATURES. 



Foruden de to vel bekj endte Lag af King- og Længde- 

 muskler, der hos Sipunclerne danne særskilte Bundter, 

 som give Huden et gittret Udseende, medens de hos Pha- 

 scolosomaerne i Eegelen danne en sammenhængende Mu- 

 skelhud, og kun hos enkelte Arter antage Form af Bund- 

 ter, have vi hos vore to nye Sipunculus- Arter fundet et 

 tredie Lag, som vi have kaldt Skraamuskellaget. Det 

 ligger imellem Ring- og Længdemusklerne i særskilte 

 Bundter, som udgjøre i Antal neppe Halvdelen af Længde- 

 musklernes. Hver Bundt er meget smalere end Længde- 

 muskelen og løber paaskraa rundt Kroppen (Tab. 13, 

 Fig. 10 s, s, s). 



Med Hensyn til den Del af Muskelsystemet, der op- 

 træder som selvstændige Muskler for Snabelen, og er kal- 

 det Ketractorer, saa have vi fundet, at de baade i Form, 

 Antal og Befæstningssteder variere overmaade meget. 

 Hvad. nu Formen betræffer, saa er den hos enkelte næsten 

 rund og danner ligesom en Søile, der staar i Midten af 

 Kropshulheden som f. Ex. hos Onchnesoma Steenstrupii; 

 hos andre ligner den en fladtrykt Cylinder, som hos Ph. 

 squamatum, hos atter andre er den ganske flad, hvilket 

 er det almindeligste. Antallet er hos alle de os bekjendte 



') Ueber den Bau und die systematische Stellung von Aspidosi- 

 phon Miilleri, Dies: Mittheilungen d. naturwissensch. Vereines für 

 Steyermark, 3. H. 1865, Pag. 56. 



Destoværre have vi ikke havt Originalaf handlingen, men kj en- 

 de den kun gjennem andre Forfattere. 



As regards the functions of these cuticular bodies 

 different opinions have been entertained. According to 

 our investigations, we must assuredly declare them to be 

 organs of secretion. We have seen in living animals 

 mucus in the form of threads coming out of the apertures 

 of the eductive canals of these organs, as also we have 

 found coagulated mucus inside them. In many of our 

 species of Phascolosoma, there is also found mucus on 

 the surface of the body, especially in the Ph. squamatum 

 the uneven skin of which is usually covered with a coat 

 of fine sand bound together with slime. Oscar Schmidt 1 ) 

 has stated that the Aspidosiphon Miilleri secretes a good 

 deal of slime, which is said to play a part in the excava- 

 tion of the galleries in the lime-stone wherein the animal 

 lives; — as also we have frequently observed that Bo- 

 nellia viridis secretes slime; so that the mucous secre- 

 tion in the Gephyreæ may probably not be so very 

 peculiar. 



The form and interior structure of the cuticular bodies 

 may furnish a good auxiliary for the diagnosis of the 

 species, when they are sufficiently well known in a number 

 of species. We have not had materials enough to establish 

 anything decided in this respect; but if it should really 

 prove to be the case, as we have some reason to anti- 

 cipate, that the form and structure of the cuticular bodies 

 are different in the different species — then the diagnosis 

 of these animals, which are often very difficult to distin- 

 guish by their exterior, will be considerably facilitated. 



THE MUSCULAR SYSTEM. 



Besides the two well known layers of annular and 

 longitudinal muscles, which in the Sipunculiform separate 

 fascicles, giving to the skin a latticed appearance, while in 

 the Phascolosoma they usually form a connected muscular 

 membrane, and only in some few species assume the form 

 of fascicles, we have in our two new species of Sipun- 

 culus found a third layer, which we have called the oblique 

 muscular layer. It is situated between the annular and 

 longitudinal muscles and lies in separate fascicles which 

 are in number about half that of the longitudinal muscles. 

 Each fascicle is much smaller than the longitudinal muscle, 

 and runs obliquely «round the body (Tab. 13, üg. 10 s, s, s). 



With respect to the part of the muscular system 

 which appears as the independent muscles for the pro- 

 boscis called retractors, we have found that they vary to 

 a remarkable extent in shape, number and attachment. 

 As regards the shape, it is in some of them nearly round, 

 and forms at it were a column standing in the middle 

 of the perivisceral cavity, as for instance in the Onchne- 

 soma Steenstrupii; in others it resembles a flattened 

 cylinder, as in Ph. squamatum ; in others again it is quite 

 flat, which is most usual. The number is, in all the 



l ) Ueber den Bau und die systematische Stellung von Aspi- 

 dosiphon Mülleri, Dies: Mittheilungen d. naturwissensch. Vereines 

 für Steyermark. 3. H. 1865, p. 56» 



Unfortunately we have not had the original treatise, but are 

 acquainted with it only through other authors. 



