I 



144 



Loupeforstørrelse. Snabelen, der er omtrent 2 Mm. lang, 

 forsynet med Papiller, der ere lidt større og staa meget 

 tættere end de paa Kroppen (Fig. 39 p), ender med en 

 oval knapformig Udbredning, paa hvis midterste Del fin- 

 des en rund, lidt foldet Mundaabning (Fig. 39 o). Hu- 

 den glindsende, gjennemsigtig, temmelig tynd, men fast, 

 har paa sin indre Flade to tynde Muskellag, uden at sær- 

 skilte Muskelbundter dannes. En Retractor, der tager 

 sit Udspring med en lidt bredere Basis paa den bagerste 

 Fjerdedel af Kropsvæggen, omtrent 2 Mm. fra Bunden, 

 følger Bugfladen langs hele Snabelen indtil dennes for- 

 reste Ende, hvor den insererer sig. Spiserøret, der er 

 langt og meget smalt, følger Retractor næsten henimod 

 Midten af Kroppen, hvor det gjør en Bøining (Fig. 40 

 sp, sp) for at gaa over i Tarmen, som strax danner et 

 Par langstrakte løse Slyngninger (Fig 40 t), der ; gaa over 

 i mange, tætte spiralförmige Vindinger (Fig. 40 ts), som 

 tabe sig i en lang Endetarm, der udmunder paa Snabelen 

 lidt foran dens Grunddel (Fig. 40 re, re). Tarmspiralen 

 er ikke befæstet i dens bagerste Ende, men vel paa dens 

 midterste Del med en enkelt tendinøs Traad. Segmen- 

 talorganet frit, ikke meget langt (Fig. 40 s). Nervestren- 

 gen temmelig tyk. Kropshulheden og de deri indeslut- 

 tede Organer beklædte med Peritoneum. 



under a strong magnifying glass. The proboscis about 

 2 Mm. long, covered with papillæ, which are a little 

 larger, and which stand more closely together than those 

 of the body (fig. 39 p), terminates in an oval button- 

 shaped enlargement, on the middle part of which there 

 is a round slightly folded oral aperture (fig. 39 o). The 

 skin is shining transparent, rather thin but firm, having 

 on its inner surface two thin layers of muscles, without 

 any separate fascicles of muscles being formed. One 

 retractor, which takes its beginning with a rather broader 

 basis, from the posterior fourth part of the wall of the 

 body, 2 Mm. from the bottom, follows the ventral surface 

 along the whole proboscis up to the anterior extremity 

 of the same, where it is inserted on the oesophagus, which 

 is long and very narrow accompanying the retractor 

 nearly to the middle of the body, where it makes a bend 

 (fig, 40 sp, sp), going over into the intestine, which im- 

 mediately forms a couple of elongated loose slings (fig. 40 t), 

 which go over into many close spiral windings (fig. 40 ts) 

 which lose themselves in a long rectum, which has its 

 aperture on the proboscis a little in front of the base 

 (fig. 40 re, re). The intestinal spiral is not attached at 

 its posterior extremity, but in its middle part by a single 

 tendinous filament. The segmental organ free, not very 

 long (fig. 40 s). The nervous cord rather thick. The 

 perivisceral cavity and the organs therein contained, 

 covered with the peritoneum. 



The color is greenish. Found by G. O. Sars at Skraa- 

 ven, Lofoten at 200—300 fathoms' depth. 



The late Professor M. Sars has called this species 

 Phascolosoma lævissimum, without however describing it. 

 As there already exists a Phascolosoma læve, and as it 

 moreover really has papillæ, we have in order to avoid 

 misunderstanding given it the name of our deceased col- 

 league and friend. 



SPECIFIC CHARACTERISTICS. 

 The body 8 Mm. long, claviform, shining, greenish, 

 with extremely small dispersed papillæ. The proboscis 

 længere end Kroppen, forsynet med Papiller, fortil en- I a little longer than the body, covered with papillæ, ter- 

 dende knapformig. Retractoren udspringer et Par Mil- | minating in front, with a button-shaped extremity. The 

 limeéer fra Kropsenden. ; retractor begins a few millimetres from the extremity of 



the body. 



Farven er grønlig. Funden af G. O. Sars ved Skraa- 

 ven, Lofoten, 200—300 Favnes Dyb. 



Afdøde Professor M. Sars har benævnt denne Art 

 Phascolosoma lævissimum, uden dog at beskrive den. Da 

 der allerede existerer en Phascolosoma læve, og den des- 

 uden virkelig har Papiller, have vi, for at undgaa Mis- 

 forstaaelse, givet den Navn efter vor afdøde Medarbeider 

 og Ven. 



ARTSCHARACTEREN. 

 Kroppen 8 Mm. lang, kølleformig, glindsende, grøn- 

 lig, med yderst smaa, adspredte Papiller. Snabelen lidt 



FORKLARING OVER FIGURERNE. 



Tal». 15, Fig. 37. Onchnesoma Sarsii, lidt forstørret. 

 Fig 38. Stærkere forstørret. 



Fig. 39. Den øverste Del af Snabelen, forstørret, o bløde Papiller 

 om Mundaabningen ; p Papiller paa Snabelens øverste Del. 



Fig. 40. O. Sarsii, aabnet og forstørret, r, r Retractor; re, re 

 Rectum; s Segmentalorgan; ep, sp Spiserøret; t Tarm; 

 ts Tarmspiral; n Nervestreng. 



EXPLANATION OF THE FIGURES. 



Tab. 15, fig. 37. Onchnesoma Sarsii, slightly magnified. 



Fig. 38. More strongly magnified. 



Fig. 39. The upper part of the proboscis, magnified, o soft pa- 

 pillæ round the oral aperture; p papillæ on the upper 

 part of the proboscis. 



Fig. 40. Onchnesoma Sarsii opened, magnified, r, r retractor; 

 re, re rectum; s segmental organ; sp, sp oesophagus; fin- 

 testine; ts circumvolution of intestine; n nervous cord*. 



