Fra den indre Flade at' Bindevævel udgaa de sæd- 

 vanlige 8 Septa, der fæste sig paa Svælgets ydre Flade. 

 Den indre Bindevævsflade er forsynet med Længde- og 

 Tvermuskler, Fig. 15, c, der gaa over paa Septa saaledes, 

 at de longitudinelle Fibre følge den ene Flade og udbrede 

 sig straalelormigt paa Svælget, og de transverselle følge den 

 modsatte Side af Septum og tæste sig ligeledes paa Svælgei. 

 Hele Mavelmlheden er beklædt med Epithel, bestaaende i 

 Reglen at' to Lag runde Celler lig dem, dia- tindes i Stam- 

 mens Længdekanaler, Fig-. 25, a. 26. I Mavehulheden, 

 Ugesom i dens forlængede Kanal, træifes otte en hel Del 

 isolerede Celler, der have nepen Lighed med Endothel- 

 cellerne, men ere noget mindre, have en klarere Membran 

 og en Kjerne, som er omgiven ai' et rigt Protoplasma. 

 Lignende Celler sees ogsaa i Hovedlængdekanalerne og 

 danne Elementer i det Fluidum, som cirkulerer i disse. 

 De have meget tilfælles med livide Blodlegemer hos høiere 

 Dyr og tungere sandsynligvis paa samme Maade, som de. 

 Septa forlænge sig ned igjennem Mavehulheden som Sep- 

 tula til det Sted, hvor denne forsnevres og gaar over i en 

 trang Kanal, — kun for de tidligere omtalte 16 — 2U Poly- 

 pers Vedkommende folge de Hovedkanalerne lige til Bunden. 



Mundaabningen danner en paatvers gauende Spalte, 

 der er bredere i den ene Mundvinkel end i den anden. 

 Læberne ere næsten lige, men paa hver Side af dem sees 

 henimod den smale Mundvinkel en liden Knude (Gronidial- 

 knude?), der synes at strække sig et Stykke ned igjennem 

 Svælget. Dette danner næsten en Cylinder, der paa sin 

 indre Flade er foldet etter Længden, paa sin ydre er glat 

 og har her en Epithelialbeklædning, bestaaende af to Lag 

 runde Celler, fuldkommen lig dem, som tapetserer Mave- 

 hulheden. Indenfor dette Endothel er et Bindevævslag med 

 Ernæringskanaler og Bindevævslegemer, Fig. 15, cl, paa 

 hvis ydre Flade, melleni denne og Endothelet, er indleiret 

 8 Længderækker Spilder, Fig. 40, der have forskjellig 

 Form og variere i Størrelse fra 0.050 — 0.120""" i Længde 

 og fra 0.008—0.010""" Bredde, Fig. 40, a. 



Den indre Flade af Svælget er foldet etter Længden, 

 og paa den iagttages langs Bugfladen en Eende (Demica- 

 naux, Hollard 1 ; Gonidial grooves, Canales gonidiales, Gosse), 

 der er triangulær, saaledes at den bredere Del af Trian- 



Grosse, Henry. Actiuologia Britamiica. A History of the 

 British Sea-Anemones aud Corals. 1860, pag. XV — XVII 

 and 4. 



Hollard, H. Monographie anatomique du genre Actiuia de 

 Linn.', considéré comme type du groupé general des Poly- 

 pea Zoanthaires. Annales des Sciences natur. Zoologie, 

 .'. Ser. Tom. XV, pag '274. 



Hertwig, Richard et Oscar. Die Actinien. Jenaische Zrit- 

 schrift f. Naturwissenschaften. 13 B., pag 512—13. 1879. 



From the inner surface of the connective-tissue, the 

 usual 8 septa proceed. whieh attach themselves to the ex- 

 terior surface of the gullet. 



The inner connective-tissue surface is furnished with 

 longitudinal and transversal muscles, (Pl. I, fig. 15 c), whieh 

 are produced into the septa in such manner, that the lon- 

 gitudinal tibres follow the one surface and spread radially 

 on the gullet, and the transversal tibres follow the opposite 

 side of the septum and, also, attach themselves to the gullet. 

 The entire ventral-cavity is clad with epithelium, consisting, 

 as a rule, of two lavers id' round cells like those found in 

 the longitudinal ducts of the stem, (Pl. 1, 25, a, 26). ln the 

 ventral-cavity, as well as in its prolonged duct, a large num- 

 ber of isolated cells are frequently met with; these have some 

 resemblance to the endothelial cells, but are somewhat smaller, 

 and have a more translucent membrane, and a nucleus sur- 

 rounded by a rich protoplasm. Similar cells are, also, observed 

 in the chief longitudinal ducts, and form an element of the fluid 

 circulating in them. They have much in eommon with 

 the white blood-corpuscles ol the higher animals and, pre- 

 sumably, perform a similar function to what they do. The septa 

 prolong themselves down through the ventral eavity as sep- 

 tula, until they attain the situation where it becomes con- 

 stricted and is produced as a straitened duct. Only in 

 regard to the 16 — 20 polyps previously spoken olj do the 

 septa follow the chief ducts right down to their bottom. 



The oral aperture forms a transversal fissure, whieh is 

 broader in the one labial angle than in the other. The 

 labiæ are almost straight, but on eaeh of them, towards 

 the narrower labial angle, a small knot is visible (Gonidial 

 knot?) whieh appears to extend itself a little down through 

 the gullet. This forms a cylinder, nearly, whieh on it 

 inner surface is folded longitudinally, and on its outer 

 surface is smooth and has, here, an epithelial coveriug 

 consisting of two layers of round cells, exactly like 

 those that line the ventral eavity. Inside of this endothel- 

 ium, there is a layer of connective-tissue, containing nutritory 

 ducts and connective-tissue corpuscles, (Pl. I, fig. 15 d); on 

 whose exterior surface, between it and the endothelium, 8 

 longitudinal series of spicules are entrenched, (Pl. 1, fig. 40), 

 whieh have different forms, and vary in size from 0.050 — 

 0.120""" in length, and from 0.008—0.010""" in breadth, 

 (Pl. I, fig. 40 a). 



The inner surface of the gullet is folded longitudinally 

 and, on it, there is observed along the ventral surface, a 

 channel (Demi-caneaux, Hollard 1 — gonidial grooves, — Canales 

 gonidiales, Gosse) whieh is triangular, in such manner, that 



1 Grosse, Henry. Actiuologia Britamiica. A History of the 

 British Sea-Anemones and Corals. I.S60, pag XV — XVII 

 aud 4. 

 Eollard, H. Monographie anatomique du genre Actinie de 

 Linné considéré comme type du groupe general des Poly- 

 pes Zoanthaires. Annales des Sciences natur. Zoologie 

 3. Ser. Tom. XV, pag 274. 



Hertwig, Richard et Oscar. Die Actinien. Jenaische /.if- 

 ichrift f. Xaturwissenschaften. 1 '■) B.. paa'. ol2 — 13. 1 V 7M. 



