S(, 



forholdsvis stor. ruml Kjerne, samt Kjernelegeme. Tab. 

 XXIII. Fig. 2 cl. Indenfor Sugevorternes ydre Epithel, 

 imellem dette og deres Bindevævslag, sees longitudinelle 

 Muskelfibre at strække sig et godt Stykke op paa Suge- 

 vorten. Tab. XXIII. Fig. 2 /: disse Sugevorter ligge i en 

 afgrændset Hule i Hudens Bindevæv, Tab. XXIII. Fig. 2 e, 

 og ere. ettersom de ere mere eller mindre indtrukne. op- 

 tagne af de fremmede Legemer, Tab. XXII. Fig. 11 c. 



Indenfor Ectodermet er et bredt, hyalint Bindevævs- 

 lag. Tab. XXII, Fig. 11 d; Tab. XXIII. Fig. 2/. hvori 

 sees mange fine Saftkanaler med deres Epithel. og i Midten 

 af dette Bindevæv tindes et temmelig bredt Belte af cir- 

 kulære Muskelfibre. der synes at danne Bundter, Tab. XXII. 

 Fig. 11 e; Tab. XXIII, Fig. 2 g. Paa Bindevævets indre 

 Væg er et Muskellag. dannet af Tver- og Længdemuskler. 

 hvoraf de sidste ere meget tydelige og stærkt udviklede, 

 Tab. XXII. Fig. 11 /, og dette Muskellag beklædes af et 

 Endothel, bestaaende af cilierende Cylinderceller, der dog 

 ikke ere saa hoie som Ectodermefs. men forsynede med lidt 

 aflange Kjerner med Kjernelegemer, Tab. XXII, Fig. 1 1 g. 



Paa Tversnit af Stilkens øverste Del sees Ectodermet 

 at beståa af meget hoie. smale, cilierende Cylinderceller 

 med store, aflange Kjerner, der indeslutte et næsten rundt 

 Kjernelegeme og ere omgivne af en tynd. kornet Proto- 

 plasmamasse, Tab. XXIII. Fig. 3 a. Hverken Slimkjertler 

 (dier Nematocyster tindes i Stilkens Ectoderm; men inden- 

 for dette er et temmelig bredt Bindevævslag, rigt paa 

 Bindevævslegemer og Ernæringskanaler, Tab. XXIII. Fig. 

 3 b. og i Midten af dette Bindevæv iagttages øverst paa 

 Stilken svage, cirkulære Muskelfibre. der blive stærkere. 

 rigere og danne Bundter. alt ettersom de komme længere 

 ned. saa at de ved Overgangen til Foden ere meget ud- 

 viklede. Tab. XXIII. Fig. 3 r. Fodskiven, der har samme 

 Struktur som Stilken, er dog rigere paa Muskelfibre end 

 denne. 



Samtlige Septa udgaa fra Bunden af Gastrovascular- 

 hulheden, nemlig fra den indre Flade af Fodskiven, Tab. 

 XXIII. Fig. 1 a, omtrent paa Midten af denne som par- 

 rede, smale, listeformige Fremspring; de strække sig langs 

 Stilkens indre Flade. bundet til dennes Bindevæv, hvoraf 

 de egentlig ere Forlængelser og ere lige brede i hele Stil- 

 kens Gastrovascularhulhed, Tab. XXIII, Fig. 4 b, som de 

 kun udfylde halvt. Tab. XXIII. Fig. 4 a. Idet de for- 

 lade Stilkens Hulhed. blive de bredere langs Kropsvæggen, 

 og her indtage de fuldstændige Septa en større og større 

 Bredde, alt eftersom de komme op inn id Underfladen af 

 Mundskiven og Svælgrøret, imedens de ufuldstændige Septa 

 synes ikke at indtage større Bredde, end de have i Stilkens 

 øverste Del. 



Their inside wall is clad with almost round reils containing 

 a relatively large round nucleus, also a nucleus-corpuscle 

 (Pl. XXIII. fig. 2 d). Inside the external epithelium of 

 the suckers. between it and their connective-tissue layer, 

 longitudinal muscle-fibres are seen to extend themselves a 

 considerable distance up the suckers (Pl. XXIII, fig. 2 i); 

 those suckers lie in a well defined cavity in the integu- 

 inental connective-tissue (Pl. XXIII. fig. 2 e), and are. ac- 

 cording as they are more or less retracted, occupied by 

 the foreign bodies (Pl. XXII. fig. c). 



Inside the ectoderm there is a broad hyaline con- 

 nective-tissue layer (Pl. XXII. fig. 11 d; Pl. XXIII. fig. 2,/), 

 in which are seen many slender nutritory ducts with their 

 epithelium, and in the middle of this connective-tissue there 

 is found a pretty broad helt of circular muscle-fibres, which 

 appear to form bundles (Pl. XXII. fig. 11 e; Pl. XXIII, 

 fig. 2 g). On the inner wall of the connective-tissue there 

 is a musculous laver, formed of transversal and longitud- 

 inal muscles, of which the last-named are very prominent 

 and strongly developed (Pl. XXII. fig. 11/), and this 

 musculous Layer is clad with an endothelium consisting of 

 ciliating cylinder-cells, which are. however, not so high as 

 those of the ectoderm. and are furnished with slightly 

 oblong nuclei and nucleus-corpuscles (Pl. XXII. fin;. 11 g). 



Upon transsection of the upperinost portion of the stem. 

 the ectoderm is seen to cmisisf of verv high, narrow. cili- 

 ating cylinder-cells coataining large oblong nuclei with an 

 almost round nucleus-corpuscle surrounded by a thin gran- 

 ular protoplasmic substance (Pl. XXIII, fig. 3 «). Neither 

 mucous dauds nor nematocysts are found in the ectoderm 

 of the stem. but inside it there is a pretty broad con- 

 nective-tissue layer,rich in connective-tissue corpuscles and 

 nutritory ducts (Pl. XXIII, fig. 3 b). and in the middle 

 of this connective-tissue there are observed, in the upper- 

 most part of the stem, delicate circular muscle-fibres. which 

 become stronger and richer and form bundles according 

 as they proceed downwards. so that at the transition to 

 the pedestal they are well developed (Pl. XXIII, fig. '■'> c). 

 The pedal disc, which has the same structure as the stem. 

 is, however. richer in muscle-fibres than it. 



All the septa issne from the bottom of the gastro- 

 vascular cavity. vi/., from the inner surface of the pedal 

 dis.- i Pl. XXIII, fig. 1 a), about the middle of it. as paired, 

 narrow, fillet-formed protuberances ; they extend themselves 

 along the inner surface of the stem. adherent to its con- 

 nective-tissue ut which they are really prolongations. and are 

 Uniform in breadth through the whole of the gastro-vasculnr 

 cavity of the stem (Pl. XXIII. fig. 4 b). which they only 

 half occupy (Pl. XXIII. fig. 4 a). As they pass from the 

 cavity of the stem they become broader along the body- 

 wall. and here the perfect septa occupy a greater and 

 greater breadth according as they pass up towards. the 

 under surface of the oral disc and the cesophagus, whilst 

 the imperfect septa do not appear to occupy a greater 

 breadth than they have in the uppermost part of the 

 stem. 



