De transverselle Muskler ere temmelig udviklede og 

 danne en foldet Lamel, der kan sees med blotte Øie. Saa- 

 vrl de primære som secundære Septa ere fuldstændige, — 

 de inserere sig alle paa Svælgrøret, men tiere af de 18 

 Par secundære Septa smelte sammen, idet de ere komne 

 nogle Millimeter fra Svælgrøret, saaledes, at det her ser 

 ud, som om der kun er et Septum og ikke et Par: samt- 

 lige ere golde. De tertiære Septa udgjør 72 Par; de ere 

 ufuldstændige, fæste sig altsaa ikke paa Svælgrøret, men ere 

 dog saa lange, at de naa næsten lien til samme. Deres 

 Muskulatur er omtrent lige saa stærkt udviklet som den 

 paa de secundære Septa. Ogsaa her beklædes den indre 

 Flade af ethvert Septum med de buskformede, longitudi- 

 nelle Muskler, Tab. IX, Fig. 7 a, imedens de ydre Flader 

 indtages af de transverselle Muskler. Alle disse Septa 

 bære Generationsorganer, der ere fuldt udviklede, saa ikke 

 alene Æg tindes i alle Udviklingsstadier, men ogsaa mange 

 Embryoner kunne iagttages, Tab. IX, Fig. 7 b. De kva- 

 ternære Septa udgjor ligeledes 72 ; men her ere de enkelte, 

 danne ikke Par og ere meget korte, neppe halvt saa lange 

 som de tertiære. De ere placerede imellem hvert 2 Par 

 af de tertiære, ere vel forsynede baade med longitudinelle 

 og transverselle Muskler og bære ligesom de tertiære Septa 

 Generationsorganer, som ere fulde af Æg og Embryoner 

 Tab. IX, Fig. 7 c 



Testikler ere ikke at opdage, saa det sandsynligvis er 

 en Hun, jeg har havt med at gjøre; derimod sees enkelte 

 Acontier, der synes at være løsrevne fra de tertiære Septa. 

 Men i det Hele tåget ere de Acontier, som ere iagttagne, 

 meget faa. 



Man har kaldt de golde Septa for Muskelsepta, fordi 

 Muskulaturen hos dem skulde være langt mere udviklet 

 end Tilfældet skulde være hos de øvrige Septa, der ere 

 blevne kaldte Generationssepta. Ja, der er enkelte For- 

 fattere, som endog benægte Tilstedeværelsen af Muskler 

 paa de Septa, der bære Kjønsorganerne. Hos alle de Ac- 

 tinier, jeg har havt Anledning til at undersøge, har samt- 

 lige Septa, baade de golde og de kjonsbærende været for- 

 forsynede med Muskler; men hos enkelte Arter har Mus- 

 kulaturen været mindre udviklet paa de Septa, der bære 

 Generationsorganerne, end paa de golde. 



Parieto-basilarmuskelen er tyk, stærk og strækker sig 

 et godt Stykke op over Kroppens indre Flade, ligesom den 

 udbreder sig over Fodskiven. 



Findested. 

 Station 260. Et Exemplar. 



on the half of the septum that faces the gastric wall, than 

 on the inner half that faces the æsophagus. 



The transversal muscles are pretty well developed, 

 and form a folded lamella which is visible to the naked 

 eye. Both the primary and the secondarv septa are per- 

 fect. They are all inserted in the æsophagus, hut several 

 of the IS pairs of secondarv septa run together. at a point 

 a t'vw millimetres after they pass from the æsophagus, so 

 that, here, it appears as if there was univ one septum, 

 and not a pair. They are all sterile. The tertiary septa 

 eunsist of 72 pairs; they are imperfect, and therefore do 

 not attaeli tliemselves to the æsophagus, but are, yet, so 

 long that they almost extend to it. Their musculosity is 

 about as powerfully developed as that of the secondary 

 septa. Here, also, the inner surface of each septum is 

 clothed with the frutiform longitudinal muscles (Pl. IX. 

 tig. 7 a), whilst the outer surfaces are occupied by the 

 transversal muscles. All these septa carry reproductive 

 organs that are fully developed, so that not only are ova 

 found in all stages of development, but also many embryons 

 may be observed (Pl. IX. fig. 7 b). The quaternary septa 

 consist. also, of 72, but here they are single and do not 

 form pairs, and are very short, scarcely half the length of 

 the tertiary. They are placed between each 2 pairs of 

 the tertiary septa, and are well supplied with longitudinal 

 and transversal muscles ; and, like the tertiary septa, they 

 also carry reproductive organs which are filled with ova 

 and embryons (Pl. IX, fig. 7 c). 



Testicles can not be observed, so that it probably is a 

 female I have had under investigation. On the other 

 hand a few acontia are seen, which appear to be sundered 

 from the tertiary septa, but, altogether, the acontia which 

 are observable are very few in number. 



The sterile septa have been termed muscle-septa, 

 because the musculosity in them is said to be much more 

 fully developed than is the case with the other septa, which 

 have been termed reproductive septa. Indeed, there are 

 some writers who even deny the presence ot muscles on 

 the septa that carry the sexual organs. In all the Act- 

 inaria which I have had an opportunity of examining, 

 the whole of the septa, both the sterile ones and the 

 reproductive ones, have been furnished with muscles, but 

 in some species the musculosity has been less developed 

 on the septa carrying the reproductive organs than on the 

 sterile ones. 



The parieto-basilar muscle is thick and strong, and 

 extends itself a considerable way up over the inner surface of 

 the body. whilst it also distributes itself over the pedal disc. 



Habitat. 

 Station No. 260. One specimen. 



