152 



4—5""" fra Mundskiven, Tab. XVIII, Fig. 5 c, hvorimod 

 det tindes paa hele den bagre Del, naar undtages dennes 

 Ende. som er forsynet med en rund Aabning (Anus), der 

 udvider og sammentrækker sig. og hvorigjennem udskydes 

 Excrementproppe, bestaaende af Grus og Slim, Tab. XVIII 

 Fig. o cl. Paa den øverste (forreste) nøgne Del, som 

 udvider sig noget op imod Mundskiven. fremtræde de 12 

 Ribber end tydeligere, og imellem dem sees Sugevorterne 

 tydeligere og ere lidt større end paa den ovrige Del af 

 Kroppen. 



Mundskiven er en god Del bredere end Kroppens forreste 

 Rand; den er temmelig plan. men foldet og lidt fordybet 

 mod den i Centrum værende, lidt aflange Mundaabning, 

 Tab. V, Fig. 4; Tab. XVIII. Fig. 5. 7. Folderne, der 

 udgaa fra Munden straaleformigt mod Peripherien , ere 

 smalest ved deres Udspring, men blive alt bredere mod 

 Mundskivens Rand. som er forsynet med 12 Tentakler, der 

 staa i en Række. Tab. V, Fig. 4; Tab. XVIII. Fig. 7. 

 Disse ere temmelig korte, tykke ved Grunden og retraktile. 

 Saavel Tentaklerne som Mundskiven og hele den forreste, 

 nøgne Kropsdel kunne trække sig ind i det skedeformige. 

 slimede Overtræk, der da synes at danne et Ror. som 

 lukker sig foroven. Dette Ror er forresten meget tyndt. 

 gjennemsigtigt og løsner meget let fra Kroppen, men er 

 dog saavidt fæstet til Længderibberne, at Dyret ikke ganske 

 kan skille sig ved det. Løsrevne Stykker erstattes hurtigt 

 ved Afsondring af en seig Materie fra den blottede Krops- 

 overflade, 



Farven. Røret eller det slimede Overtræk er skjønt, 

 dybt kastaniebrunt, spillende lidt i det Violette. Kroppens 

 Hud bleg rosenrød. Mundskiven og Tentaklerne ere intens 

 karmosinrode. dog er Skiven lidt blegere end Tentaklerne, 

 Tab, V. Fig. 4. 



Ved at aabne Dyret efter Længden falder det strax 

 i Ørnene, at man her har med en indre Ordning, lig den. 

 der er beskreven for Fenja mirabilis. Her er ingen 

 Gastrovaseiilarhulhed. idet nemlig Spiserøret fgaar umid- 

 delbart over i en vel udviklet Tarm. som ender i en Anus, 

 Tab. XVIII. Fig. 7. 



Spiserøret er cylindrisk, 8'"'" langt. 4""" bredt lige ved 

 Mundaabningen, Tab. XVIII. Fig. 7 a, men aftager noget 

 i Tykkelse, idet det gaar over i Tarmen, Tab. XVIII, Fig. 

 7 b. Denne udvider sig lidt. strax nedenfor Øsophagus, 

 og gaar i næsten lige Retning henimod den bagerste Em le. 

 hvor den atter udvider sig en Smule, for som Rectum, 

 Tab. XVIII, Fig. 7 c, at ende i den runde Anus. Paa 

 den udvendige Side af Spiserør og Tarm sees Insertionerne 

 for 12 Septa, Tab. XVIII, Fig. 7 cl. som dele hele Diges- 

 tioiisapparatet i 12 Længdefelter, Tab. XVIII. Fig. 7; i 

 en Afstand a f et Par Millimeter fra Anus iagttages paa 

 Tarmen (Rectum), just i hvert Længdefelt. altsaa imellem 

 hver 2 Septainsertioner. en yderst fin Spalte, der er omtrent 

 2 mm lang, Tab. XVIII, Fig. 7 e. og som vi senere skulle 



not cover the whole of the body. as the uppermost part 

 is exposed for a length of 4- 5""" from the oral disc (Pl. 

 XVIII. fig. 5 et. but, on the other hand, it is found covering 

 the whole of the posterior part. with exception of the 

 extremity. which is furnished with a round aperture (anus') 

 that dilates and contracts itself, and through which the 

 exerementa are ejected in the shape of plugs of coarse 

 sand and mucous (Pl. XVIII. fig. 5 cl), ln the superior 

 (anterior) naked part, which dilates itself somewhat towards 

 the oral disc. the 12 ribs appear still more distinctly, and 

 between them the suckers are more distinctly observed, 

 and are a little larger than on the rest of the body. 



The oral disc is a nood deal broader than the anterior 

 margin of the body; it is rather plane, but folded, and is 

 a little depressed towards the slightly oblong, oral aperture 

 situated in the middle (Pl. V. fig. 4; Pl. XVIII, figs. 5. 7). 

 The folds, which issne from the oral aperture, radially. 

 towards the periphery, are narrowest at their origin. but 

 gradually become broader towards the margin of the oral 

 disc. which is furnished with 12 tentacles standing in a 

 series (Pl. V. fig. 4 ; Pl. XVIII, fig. 7). These are rather 

 short. thick at the base and retractile. The tentacles as 

 well as the oral dise and the entire anterior exposed part 

 of the body, are capable of being withdrawn into the 

 vaginal mucous covering, which then appears to form a 

 tube that closes itself at the top. This tube is, otherw ise. 

 \. r\ thin. transparent, and easily detached from the body. 

 but is. vet, so well secured to the longitudinal ribs that 

 the animal cannot quite throw it off. Detached portions 

 are quickly replaced by exudation of a viscid substance 

 from the naked exterior surface of the body. 



lin' colour. The tube. oi the mucous covering, is a 

 beautiful, chestnut brown; having a violet play of colour. 

 The integunient of the body is pale rosy-red. The oral 

 disc and the tentacles are an intense crimson-red. but the 

 disc is a. little paler in colour than the tentacles (Pl \. 

 fig. 4). 



Upou dissecting the animal longitudinally, it hnmedi- 

 atelj becomes evident, that we have. heie. an internal arrange- 

 ment like that described in connection with Fenja mirabilis. 

 Here there is an absence of any gastro-vascular cavity, as the 

 gullet-tube pusses immediately over into a well-developed 

 intestine that terminates in an anus i Pl. XVIII, fig. 7). 



The gullet-tube (æsophagus) is cylindrical, 8°"" in 

 length, and 4""" in breadth just at the oral aperture (Pl. 

 XVIII. tin. 7 a), diminishing somewhat in thickness as it 

 passes over into the intestine (Pl. XVIII, fig 7 V). The 

 intestine becomes a little dilated immediately below the 

 æsophagus, and passes, in almost a straight line, towards 

 the posterior extremity, where it again dilates itself a little. 

 in order to. as a rectum (Pl. XVIII. fig. 7 c), terminate 

 in the round anus. On the exterior side of the gullet- 

 tube and intestine the insertions of 12 septa are observed 

 (Pl. XVIII, fig. 7 il), which divide the entire digestive ap- 

 paratus into 12 longitudinal areas (Pl. XVIII, fig. 7); at a 

 distance of a couple of millimetres from the anus. there is 

 seen on the intestine i rectum |, exactlvin each longitudinal belt. 



