183 



der i Cellens nedre Del fine Spalter i de sammenvoxede 

 Vægge, hvorved samtlige Celler kommunicere med hverandre. 



Polypkroppen er udvendig beklædt med et Epithel, 

 bestaaende af to Lag polyædriske Celler, fuldkommen lig 

 dem, som tindes paa Polypcellerne, Tab. XX. Fig. 1. a. 

 og her tindes i det indre Lag af Ectodermet pæreformige, 

 encellede Slimkjertler. Indenfor Ectodermet er et tyndt. 

 hyalint Bindevæv, hvori sees yderst fine Ernæringskanaler, 

 udfyldte med Epithel, samt spredte Bindevævslegemer med 

 Udløbere. Imellem Ectodermcellernes indre Lag er en 

 rig Spikelafsætning, ligesom inde i selve Bindevævet sees 

 hist og hér Spikler, men altid omgivne af Ectodermceller, 

 Tab. XX, Fig. 1. b. Fra den indre Yæg af Bindevævet 

 udgaa de 8 Septa, der dannes at' Bindevævsforlængelser, 

 og der. hvor de tåge sit Udspring, ligesom der. hvor de 

 fæste sig paa Svælgrøret, er Bindevævet triangulært udvidet, 

 Fig. 1, c. 2. a. Septa ere paa den ene Side forsynede med 

 næsten transverselle Muskelfibre, Fig. 2. b. imedens den 

 modsatte Side har longitudinelle Muskler, Fig. 2, c; begge 

 gaa ikke alene over paa Svælget, men ogsaa paa omtrent 

 Halvdelen af Mavehulhedens indre Væg (Kammervæg), 

 Fig. 1, e. 2, d. Muskellagene, Svælget og hele Kammer- 

 væggen har et Epithelovertræk, Endothel. bestaaende af 

 et Lag temmelig smaa. runde Celler med Kjerne og Kjerne- 

 legeme, Fig. 1, (I. 2, e. Forholdet er her omtrent det 

 samme, som omtaltes under Polypcellernes Organisation. 

 Septa ere forholdsvis meget lange, hvorved Kamrene blive 

 usædvanligt store, Tab. XX, Fig. 2 A, a. 



Svælgrøret er temmelig langt, næsten cylindrisk, for- 

 synet med 6 enkle Længderækker Spikler, 3 paa hver Side, 

 og har paa sin ydre Flade. foruden Endothelet, et hyalint 

 Bindevævslag, der er meget bredt paa de Steder, hvor 

 Septa støder til, Tab. XX. Fig. 2, /'; paa Svadgets indre 

 Flade iagttages langs Bugsiden den brede, ovale Svælg- 

 rende, der har en Indbugtning just paa det Sted, hvor 

 Dorsalsiden tager sin Begyndelse, Tab. XX, Fig. 2. g. 2 A, b. 

 Svælget kan her snøre sig saaledes sammen, at Svadgrenden 

 danner en Hulhed for sig selv, som sandsynligvis bliver 

 uberørt af de Excrementer, der udføres af Mavehulheden, 

 og som passerer igjennem den anden større Hulhed langs 

 Rygsiden. Paa flere Exemplarer viste denne Indsnøring 

 af Svælget sig meget tydeligt paa T versn it. hvorved det 

 ligesom deltes i 2 cylindriske Hulheder. Svælgrenden er 

 beklædt med et Epithel. bestaaende af et Lag lange 

 Cylindereeller, paa hvis Ende er et langt, svingende Haar. 

 (Pidsk, Geissel), Tab. XX. Fig. 2. h. 2 A, c; den øvrige 

 Del af Svælghulheden er ligeledes beklædt med Epithel, 

 men her ere Cellerne kortere, ligesom Cilierne ere baade 

 finere og kortere, Fig. 2, i. Imellem disse Epithelceller 



reil exteuds down to the basal part. which serves as the 

 cellular bottom, and. whilst the uppermost part is com- 

 pletely closed, there are, in the lower part of the cell, 

 minute fissures in the concreted walls, by means of which 

 all the cells communicate with each other. 



The polyp-body is clad, externally, with an epithel- 

 ium, eonsisting of two layers of polyhedrical cells exactly 

 resembling those found on the polyp-cells (Pl. XX, fig. 1, a) 

 and, here, in the inner layer of the ectoderm, piriform, 

 unicellular mucous glands are found. Inside of the ecto- 

 derm, there is a thin hyaline connective-tissue in which 

 extremely minute nutritory dncts filled with epithelium 

 are seen, and, also, scattered connective-tissue corpuscles 

 with prolongations. Between the inner layers of the ecto- 

 derm-cells there is an abundant spicular deposit, whilst, 

 also, in the connective-tissue itself spicules are, here and 

 there. seen. hut always surrounded by ectoderm-cells 

 (Pl. XX, fig. 1, b). From the inner wall of the connec- 

 tive-tissue 8 septa issue. which are formed of connective- 

 tissue prolongations, and at the point where they issue, 

 and also at the point where they attach themselves to the 

 gullet-tube, the connective-tissue is triangularly dilated 

 (Pl. XX, figs. 1, c. 2, a). The septa are furnished, on 

 the one side, with, nearly transversal, muscular fibres 

 (Pl. XX, fig. 2, b) whilst the opposite side has longitudinal 

 muscles (Pl. XX. fig. 2, c); both pass, not only over on to 

 the gullet, hut, also, on to about a half part of the inner wall 

 (chamber wall) of the gastral cavity (Pl. XX, figs. 1 . e. 2, å). 

 The muscular layers, the gullet, and the entire chamber- 

 vvall have an epithelial covering (endothelium), eonsisting of 

 a laver of, pretty minute, round, cells, each containing a 

 nucleus and nucleolus (Pl. XX, figs. 1, d. 2, e). The rela- 

 tions, here, are inuch the same as those spoken of in 

 reference to the structure of the polyp-cells. The septa 

 ure. relatively, very long, causing the chambers to be un- 

 usually large (Pl. XX, fig. 2 A, a). 



The gullet-tube is råtner long, almost cylindrical, and 

 it is furnished with 6, single, longitudinal series of spicules, 

 3 on each side; on the exterior surface, it has, besides 

 the endothelium, a laver of hyaline connective-tissue, which 

 is very broad in the situations where the septula join it 

 (Pl. XX. figs. 2. f). On the inner surface ut' the gullet, 

 along its ventral side, the broad, oval. gullet-passage is ob- 

 served; it has a concavity, just at the point where the 

 dorsal side commences (Pl. XX. tigs. 2, g. 2 A, b). The 

 gullet is. here, capable of so constricting itself, that the 

 gullet-passage forms a cavity for itself, which, probably, 

 is not affected by the excrementa expelled from the gastral. 

 cavity, and which pass through the other large cavity along 

 the dorsal side. In several specimens, this constriction of 

 the gullet showed itself very distinctly in the section. by 

 which it was, as it were, divided into 2 cylindrical cavities. 

 The gullet passage is clad with an epithelium, eonsisting 

 of a laver of long cylinder cells on whose extremities there 

 is a long waving filament (flagellum-geissel) (Pl. XX, fig. 2, /*, 

 2 i, cl; the remaining part of the gullet cavity is, like- 

 wise, clad with epithelium hut, here, the cells are shorter. 



