148 



nes Protoplasmaindhold, ganske forskjelligt fra, hvad jeg 

 omtalte at være Tilfældet bos Edwardsioides vitrea, hvor 

 Spermatozoen antages væsentlig at dannes af Cellekjernen. 



Ved at aabne Dyret efter Længden viser det sig, at 

 der ikke som hos Coelenteraterne findes nogen saakaldet 

 Gastro vascularhulhed, Tab. XVII, Fig. 1. Spiserøret, Tab. 

 XVII, Fig. 1 e, er cylindrisk, omtrent 10""" bredt ved dets 

 Begyndelse, men aftager lidt i Tykkelse i en Længde af 

 g — IQ""», hvor det gaar over i en tyk Tarm, Tab. XVII, 

 Fig. 1 f, som bliver efterhaanden lidt smalere, idet den i 

 en næsten rét Linie strækker sig ned imod den bagerste 

 Ende, hvor den gaar over i Rectum, Tab. XVII, Fig. 1 g, 

 der udmunder i den før beskrevne, runde Anus, Tab. XVII, 

 Fig. 1 h. 



Paa Spiserørets og Tarmkanalens ydre Flade fæste 

 sig 12 Septa, der som tidligere berørt, tåge deres Udspring 

 fra Kroppens indre Væg og strække sig lige fra den 

 bagerste Ende til Mundskivens Underflade . hvortil de 

 ligeledes ere bundne. Disse Septa dele Kropshullieden 

 (Coelomet) i 12 Længdekamre, som foroven; lige under 

 Mundskiven, kommunicere med hverandre, idet der i ethvert 

 Septum er en oval Aabning, just paa det Sted, hvor dette 

 fæster sig paa Mundskiven (Oral-Stomata). Bagtil er der 

 ingen saadan Kommunikation : her slutte Kamrene sig 

 omkring Rectum. men i deres Bund. der dannes af Krops- 

 huden, som her er noget fortyndet. tindes imellem de før 

 beskrevne Papiller, eller egentlig Endeinsertionerne for 

 Septa bagtil. en fin Spalte, der lukkes og aabnes ved en 

 Fold. som synes at danne en Slags Klappe, Tab. XVII. 

 Fig. 12 a, 13 ff. Denne Spalte sætter hver Kam i For- 

 bindelse med det ydre Medium (Sovandet). og maa egentlig 

 betragtes som Genitalpore. Hvorvidt der igjennem disse 

 Spalter strømmer Søvand ind i Kamrene, er vel meget 

 tvivlsomt; jeg har Intet kunnet iagttage i saa Henseende. 

 Paa et Exemplar er den yderste Ende af Rectum med 

 sin Anus skudt lidt frem ved Kontraktion, og en Excre- 

 mentprop af slimholdigt Sand udfvldte Anus. Ved at 

 borttage denne Prop sees Folderne paa Rectums indre 

 Væg, Tab. XVII. Fig. 4 c. 



Paa Spiserørets indre Væg er der overmaade mange 

 Længdefolder, der ere afbrudte ved Kontraktioner af Tver- 

 muskler, hvorved Folderne faa Udseende af at løbe paa- 

 tvers, Tah. XVII. Fig. 2 a. Dette Forhold forandrer sig, 

 saa snart Øsophagus er gaaet over i Tannen, thi her 

 fremtræder Længdefolderne meget tydeligere, om end de 

 ogsaa her paa Grund af Tvermusklernes Virkning har et 

 bolgeformigt Udseeude. Tab. XVII. Fig. 2 b ; men i Rectum 

 ere de endnu tydeligere, tykkere og lobe i næsten rette 

 Linier ned til Anus. Tab. XVII, Fig. 2 c, hvorom de 

 samle sig, Tab. XVII, Fig. 2 d. Der er ingen Svælg- 

 grube. 



the sperrnatoblast's protoplasmic contents, perfectly different, 

 therefore, from what I stated to be the ,case in Edwardsi- 

 oides vitrea, where the spermatozoa is supposed to originate 

 principally in the cellular nucleus. 



On dissecting the animal longitudinally it appears, 

 that unlike the Coelenterata, there is no so-called gastro- 

 vascular cavity to be found (Pl. XVII. fig. 1). The gullet- 

 tube i Pl. XVII, fig. 1 e) is cylindrical, and about 10""" 

 in breadth at its origin, hut diminishes a little in thickness 

 for a distance of 8 — 10'"™, and tlien passes over into a 

 thick intestine (Pl. XVII, fig. 1 f), which becomes grad- 

 ually narrower as it. in almost a straight line, extends 

 itseif down towards the posterior extremity, where it passes 

 over into the rectum (Pl. XVII, fig. 1 g), which opens into 

 the previously described round anus iPl. XVII, fig. 1 ln. 



Ipon the outer surface of the gullet-tube and intes- 

 tinal canal 12 septa are adherent, which, as previously 

 merrtioned, have their origin in the inner wall of the body 

 and extend themselves quite from the posterior extremity 

 to the under surface of the oral disc, to which also they 

 are attached. These septa divide the body-cavity (the 

 Coelonn into 12 longitudinal chambers, which, at the top, 

 just under the oral disc. communieate with each other, in 

 as much. that there is. in each septum, an oval aperture 

 just at the point where the septum is secured to the oral 

 dise (oral-stomata). There is no such comniunieation pos- 

 teriorly; here the chambers close round the rectum, but 

 at their bottom — formed by the body integument, which 

 is here somewhat less thick — between the previously men- 

 tioned papillæ or. really, the terminal posterior insertions 

 of the septa. there is found a fine fissure, which is opened 

 and elosed bj a lidd thai appears to form a kind of valve 

 (Pl. XVII. fig. 12 a, 13 a). This tissure places each 

 chamber in communieation with the external medium (the 

 sea-water), and must he regarded as really a genital pore. 

 Whether the sea-water flows into the chambers through 

 these fissures is. indeed, verv doubtful; I have been unable 

 to detect anv indications ot this. In one specimen the 

 extreme end ol the rectum with its anus, is a little pro- 

 jected by contraction, and an excrementory plug of slimy 

 sand occupies the anus. On removing this plug the folds 

 of the inner wall of the rectum become visible (Pl. XVII, 

 fig. 4 c). 



On the inner wall of the gullet-tube there are an 

 immense number of longitudinal folds, which are broken 

 ofl' by the contractions of the transversal muscles causing 

 the folds to acquire the appearance of running transversally 

 (Pl. XVII. fig. 2 a). This relation changes as soon as 

 the cesophagus passes over into the intestine; the longi- 

 tudinal folds appear, here, much more prominently, although 

 they also. here, have a bulging appearance, owing to the 

 action of the transversal muscles (Pl. XVII, fig. 2 &), but 

 in the rectum tln\ are still more distinct and thicker, 

 and extend in nearly straight lines down to the anus (Pl. 

 XVII, fig. 2 c), round which they collect (Pl. XVII, fig. 

 2 d). There is no gullet-groove (syphonoglyphe). 



