2(3 



felter, hvori sees en Mængde Bindevævskjerner og Er- 

 nærineskanaler, Tab. X. Fie. 1 c. 



Der er 6 Par principale Septa, der tillige ere fuld- 

 stændige, forsaavidt de fæste sig paa Svælget, og disse 

 Septa ere meget tykke, brede og faste, men golde ; de ere 

 forsynede med bande Længde- og Tvermuskler, af hvilke 

 de fniste danne udprægede, foldede Lameller, Tab. X, Fig. 

 1 å, e. Der er altsaa 6 principale Kamre; i ethvert af 

 disse er der et Par secundære Septa. der ikke heste sig 

 paa Svælget, men naa næsten lige hen til dette, ere langt- 

 fra saa tykke og brede, som de principale, og bære foruden 

 Mesenterialfilamenter. Kjonsorganerne, der ere fuldt udvik- 

 lede og indeholde Æg i næsten alle Utviklingsstadier. 

 Kjønnet synes at være adskilt; thi kun Æg fandtes over- 

 alt; det kan dog hænde, at en eller anden Testikel kau 

 have skjult sig, trods den omhyggeligste Undersøgelse. 



Ingen Acontier; begge de fundne Exemplarer ere 

 med Hensyn hertil paa det samvittighedsfuldeste undersøgte; 

 men intet Spor deraf var at opdage. Det er ikke forbun- 

 den med synderlige Vanskeligheder at tinde Acontierne, 

 hvor de ere tilstede, saa man kan være forvisset om. at 

 Acontier mangler lier. 



De tertiære Septa ere meget korte . men temmelig 

 tykke og udgjore 12 Par; der er altsaa i det Hele 24 Par 

 Septa. Parieto-basilarnmskelen er ikke meget tyk og 

 strækker sig membranagtigt et Stykke opover paa Krops- 

 væggen og nedover paa den indvendige Flade af Fodskiven. 

 Her sees Insertionerne af Septa særdeles godt, og det viser 

 sig, at de primære og secundære Septa naa lige hen til 

 Skivens Centrum , imedens de tertiære Septa ikke naa 

 halvt saa langt. 



Findested. 

 Station 226. 2 Exemplarer. 



Slægtskarakter. 



Fodskiven rund med tyk Raml. Kolumnen cylindrisk, 

 tyndvægget, glat med Længdefolder og Cinclides. Mund- 

 skiven rund. Tentaklerne retraktile, alle af omtrent samme 

 Størrelse, korte, faatallige, i faa Rækker. Mesodermale 

 Cirkulærmuskler. 6 Par fuldstændige, golde Septa. Ingen 

 Acontier. 



Artskarakter. 



Fodskiven rund med tyk, unduleret Rand og stærkt 

 foldet Underflade. Kroppen cylindrisk, lidt smalere nedad 

 end Fodskiven, udvidende sig noget opad mod den øverste, 

 temmelig tynde, lidt undulerende Rand. med en glat ydre 



everywhere, occupy the middle of the connective-tissue 

 laver, so that it forms, on both the sides, broad longitu- 

 dinal folds in which a multitude of connective-tissue nuclei 

 and nutritory ducts are visible (Pl. X, fig. 1 c). 



There are 6 pairs of principal septa. which are per- 

 fect as well in so far that they adhere to the cesophagus; 

 these septa are very thick, broad and firm, but sterile; 

 they are furnished with both longitudinal and transversal 

 muscles. of which the first-nanied form prominent folded 

 lamellæ (Pl. X. fig. 1 d, e). There are, thus, (i principal 

 chambers, and in each of them there is a pair of second- 

 ary septa which do not adhere to the oesophagus but 

 extend almost up to it; they are not nearly so thick or 

 so broad as the principal septa. and they carry. besides 

 mesenterial filaments. the reproductive organs, which are 

 fully developed and contain ova in nearly all stages of 

 development. The sexes appear to he separated, as. every- 

 where, ova only were observéd; it may however be. that 

 one or other testicle lias lain concealed in spite of the 

 closest investigation. 



No acontia; both the specimens found have been sub- 

 mitted to the most scarching examination in this respect, 

 but no trace of acontia could be detected. There is no 

 verv great difficulty in detecting acontia when they are 

 present, so that we may he quite certain that acontia are 

 awanting here. 



The tertiary septa are very short but rather thick, 

 and consist of 12 pairs; there are thus 24 pairs of septa 

 altogether. The parieto-basilar inuscle is not very thick, 

 and extends itself, meinbranaceously, a lit t li > way up. over 

 the wall of the body and down on the internat surface of 

 the pedal disc. Here the insertions of the septa are parti- 

 cularly well seen, and it is apparent that the primary and 

 secondary septa reach right to the centre of the disc, 

 while the tertiary septa do not reach half so far. 



Habitat. 



Station No. 22(j. Two specimens. 



Generic characteristies. 



Pedal disc round with thick margin, the column 

 cylindrical, wall membranous, sniooth. with longitudinal 

 folds and cinclides. The oral disc round. The tentacles 

 retractile, about uniform in si/e. short, few in number, in 

 few series. Mesodermal circular muscles. 6 pairs of 

 completely sterile septa. No acontia. 



Specifie characteristies. 



The pedal disc round, with thick undulating margin and 

 strongly folded under-surface. The body cylindrical, some- 

 what narrower, below, than the pedal disc, but expanding 

 somewhat in width. upwards, towards the uppermost, rather 



