151 



Artskarakter. 



Legeme! cylindrisk, 70""" langt, 15""" bredt i den 

 forreste, konisk tilspidset i den bagre Ende, der er for- 

 synet med 12 Papiller, givende Anus et stjerneformet Ud- 

 seende. Kroppens Overflade glat med 12 Længdefurer og 

 spredte Sugevorter, som paa den forreste Kropsdel ordne 

 sig i Rækker. Huden er, naar Dyret er i fuld Vigør med 

 udstrakte Tentakler, gjennerusigtig saavidt, at Septa med 

 Mesenterialfilamenter kunne skjelnes. Mundskiven konisk 

 fremspringende med en næsten rund Mund. hvorfra udgaa 

 12 Folder mod Peripherien. Ingen G-onidier. 12 Ten- 

 takler, omtrent en Trediedel saa lange som Kroppen, 

 retraktile. slanke, endende næsten traadformigt. Kroppens 

 øverste Rand kan trækkes over Mundskiven. Under Sam- 

 mentrækningerne antager Huden en rudet Form. Farven: 

 Den forreste Del af Legemet er næsten vandklar, spillende 

 lidt i det Rode; den midterste Del kjodrød med lysere 

 Længdestriber ; den bager ste Del har. naar den er udvidet, 

 omtrent samme Farve som den forreste, men kontraheret 

 er ogsaa den kjødrød. Mundskiven næsten vandklar med 

 blegt rosenrøde, i det Violette spillende Straaler. Tenta le- 

 ierne lyserøde, næsten vandklare; ved Grunden en brun- 

 violet Flæk, forlængende sig som en Stribe langs den 

 adorale Side lige til Spidsen. 



Slægt Ægir. 



Legemet langstrakt, cylindrisk, med et slimet, skede- 

 formet Overtræk samt 12 Længderibber, iniellem hvilke 

 spredte, smaa Sugevorter. En Række faa Tentakler. Paa 

 den bagerste Del af Tarmrøret (Rectum) strax ovenfor Anus 

 12 fine Spalter, der kommunisere direkte med Tarm- 

 lumenet; 12 ligestillede, fuldstændige Septa. Endoderniale 

 Cirkulærmuskler. Hermaphrodit. 



Specific characteristics 



The body cylindrical, 70""" in length, 15'"'" in breadth 

 at the anterior extremity, conically acuminated at the 

 posterior extremity, which, latter, is furnished with 12 

 papillæ, giving to the anus a stelliform appearahce. The 

 external surface of the body smooth. with 12 longitudinal 

 furrows and scattered suckers, which in the anterior pari 

 of the body are arranged in series. The integument, when 

 the animal is in full vigour and has its tentacles extended, 

 transparent, so much so, that the septa with the mesen- 

 terial filaments may be distinguished. The oral disc con- 

 ically protuberant, has an almost round oral aperture from 

 which 12 folds issne towards the periphery. No gonidia. 

 12 tentacles of about a third part the length of 

 the body. retractile, attenuated, terminating almost fila- 

 mentously. The uppermost margin of the body may be 

 drawn over the oral disc. During the contractions the 

 integument acquires a chequered form. Tlie colour. The 

 anterior part of the body is almost pellucid, with :i red- 

 dish play of colour; the media! part is fiesh-coloured with 

 lighter coloured longitudinal stripes; the posterior part 

 has, when it is extended, about the same colour as the 

 anterior part, but when contracted is also Hesh-coloured. 

 The oral disc is almost pellucid. with faint rosy-red rays 

 having a violet play of colour. The tentacles light-red, 

 almost pellucid; at their base a brown, violet patch pro- 

 longing itseli as a stripe along the adoral side right up 

 to the point. 



Genus Ægir. 



The body elongate, cylindrical. with a mucous vaginal 

 covering, and 12 longitudinal ribs between which small 

 suckers are scattered. One cycle of few tentacles. In 

 the posterior part of the intestinal canal (rectum), im- 

 mediately above the anus. 12 slender tissures that communi- 

 cate directly with the intestinal passage. 12 similarlv situ- 

 ated perfect septa. Endodermal circular muscles. Her- 

 maphrodite. 



Ægir frigidus. 



Tab. V, Fig. 4: Tal.. XVIII, Fig. 5-10; Tab. XIX, Fig. 1—4. 



Legemet cylindrisk, omkring 30""" langt, 8 — 10""" 

 bredt i den forreste og -1— 5""" bredt i den bagerste. noget 

 afrundede Ende, Tab. V, Fig. 4. Kroppens Overflade har 

 et yderst tyndt, slimet, lidt inkrusteret Overtræk og er 

 forsynet med' 12 temmelig fremspringende Ribber, Tab. 

 XVIII, Fig. 5 a, imellem hvilke findes lidt fordybede 

 Længdefelter, Tab. XVIII, Fig. 5 b, hvori der ved Hjælp 

 af stærk Loupe sees smaa, spx - edte Sugevorter, som synes 

 at staa to og to sammen. Det nævnte Overtræk, der er 

 temmelig fast bundet til Ribberne, dækker ikke hele Krop- 

 pen; t hi dennes øverste Del er nogen i en Længde af 



Ægir frigidus. 



Pl. V, fig. 4; Pl. XVIII, figs. r.— 10; Pl. XIX, figs. 1—4. 



The body cylindrical, about 30 mm in length, 8—10"™ 

 in breadth at the anterior extremity. and 4 — 5""" in breadth 

 at the posterior, somewhat rounded extremity (Pl. V, fig. 4). 

 The external surface of the body has an extremely thin, 

 slightly encrusted. mucous covering, and is furnished with 

 12 rather protuberant ribs (Pl. XVIII, fig. 5 a) between 

 which slightly depressed longitudinal areas are found 

 (Pl. XVIII, fig. 5 b), in which, with the aid of a powerful 

 magnifying glass, small, scattered suckers are seen, which 

 appear to stand two and two together. The covering 

 mentioned is pretty firmly attached to the ribs, and does 



