12 



og 4 i Indsnittene, Tab. VII, Fig. 8. Fra Randen ud- 

 gaa straaleformigt mod Centrum 40 temmelig skarpe Linier, 

 der svare til Randens Furer, og som antyde Insertionerne 

 af Septa. 



Kroppen bægerformigt udvidet mod Mundskiven, 

 næsten vandklar, forsynet med 4n Ribber, iler ere hredest 

 paa Midten, men blive smalere saavel ned imod Fodranden 

 som op imod Mundskiven. Paa disse Ribber sees i per- 

 pendikulære Rækker temmelig fcæt staaende smaa, isolerede, 

 hvide. runde Punkter, der ikke rage op over Hudens Niveau, 

 men have en Fordybning i Sugehuler, Suckers?), hvortil frem- 

 mede Legemer hæfte sig. Tab. VII, Fig. ti. 7. Flere af 

 disse Sugehuler syntes at være perforerede, saa at de kor- 

 responderede med Kamrene. [mellem hver 2 Ribber er 

 en yderst lin Fure, der svarer til Insertionerne af Septa 

 paa Kroppens indvendige Flade, Tab. I. Fig. .'i. Tab. VII. 

 Fig. (i, 7. Hele Kropsvæggen er saa gjennemsigtig, at 

 ikke alene Septa. men Svælget. Mesenterialfilamenterne og 

 Kjønsorganerne tydelig kunne sees. 



Mundskiven er omtrent 45 bred, svagt hvælvet og 

 tint foldet. Folderne udgaa som divergerende Straaler fra 

 Mundaabningen til Peripherien og tiltage i Tykkelse suc- 

 sessivt, idet de synes at gaa over i Kroppens Ribber, Tab. 

 VII, Fig. 6, 7. Imellem disse Folder tindes tine Furer, 

 hvori tydeligt kan sees Insertionerne af Septa. Tab. VII, 

 Fig. 6, 7. Mumien er afiang, lidt konisk fremtrædende 

 med en smal Gonidiefure paa hver Side; Læberne temme- 

 lig tykke, foldede. Tab. I. Fig. 3; Tab. VII. Fig. ti. 

 Mundvigene. hvorfra Gronidiefurerne udgaa, svare i Ret- 

 ning til de paa Podskiven omtalte 2 halvmaaneformige 

 Indsnit. 



Tentaklerne sidde i to Rækker, 24 i hver. Di' eie 

 retraktile. tykke og omtrent halvt saalange sinn Mundski- 

 vens Bredde. Den inderste Række indtager Mundskivens 

 Peripheri og ere lidt hengere end de. der danne yderste 

 Række, og som sidde paa Kroppens øverste Raud. der ikke 

 kan trækkes over Mundskiven. Tab. I, Fig. 3; Tab. VII, 

 Fig. 6. Naar Dyret er sammentrukket, danner del en glat 

 Halvkugle, hvoraf Mundskiven udgjør det øverste BEvælv. 



Kroppens ydre Væg er som sædvanligt beklædt med 

 et Ectoderm, bestaaende af lange Cylinderceller, forsynede 

 med Cilier, Tab. VII. Fiii. 9 a, og imellem hvilke sees af- 

 lange. encellede Slimkjertler. I det temmelig brede Binde- 

 vævslag sees vel udviklede, cirkulære Muskelfibre, Tab. VII, 

 Fig. i' c, der ligge nærmere den entodermale end ectoder- 

 male Side. saa at der imellem Entodermet og Muskelfibrene 

 er kun et smalt Belte af Bindevævslaget, imedens dette er 

 meget bredt mod Ectoderinet, og i denne brede Del iagt- 

 tages Bindevævslegemer med en eller flere Qdløbere, Tab. 

 VII, Fig. li h, Paa Bindevævets indre Flade erEndothelel 

 med sim- lange Pidskeceller, Tab. VII. Fig. '.i d. 



as it were, in such manner, that there are 18 folds on 

 each of its sides and 4 in the incisions i Pl. VII. fig. s ). 

 From the margin their issue radially, towards the centre, 

 40 rather sharp lines which correspond to the furrows of 

 the margin, aud which indicate the insertions of the septa. 



The bodj is expanded, in crateriform, towards the 

 oral disc, is almost pellucid, and furnished with 40 ribs 

 which aie broadest at the middle. but become narrower 

 lioth down towards the basal margin as well as up towards 

 the oral disc. On these ribs. placed in vertical series and 

 rather closely situated, small, isolated^ white, round points 

 are observed, which do not project beyond the integumental 

 surface, but have a depression (loopholes, suckers) to which 

 foreign bodies adhere (Pl. VII. tigs. ti. 7). Several of 

 these loopholes appeared to be perforated. so that thev 

 corresponded whith the chambers. Between each 2 ribs 

 there is an extremely slender furrow which corresponds to 

 the insertions of septa on the interior surface of the body 

 (Pl. I. rig. 3; Pl. VII. rigs. ti. 7). The entire body-wall 

 is so transparent, that not onlv the septa. but also the 

 iphagus, mesenterial filaments and reproductive organs 

 may be distinctly seen. 



The oral disc is about 45""" in breadth, faintly arcu- 

 aie, and rinelv folded. The folds issne as diverging ravs 

 from the oral aperture to the periphery, and increase pro- 

 gressivelv in thickness, until thev appear to pass over into 

 the ribs of the body (Pl. Vil. figs. 'i. 7). Between these 

 folds slender furrows are found, in which the insertions of 

 septa can be distinctly seen (Pl. VII. rig. ti. 7). The 

 ' mouth is oblong, a little conically projectant, with a nar- 

 row gonidial groove on each side. The labiæ are rather 

 tin. k. and folded (Pl. I. rig. 3: Pl. VII. fig. 'i : the oral 

 angles from which the gonidial grooves issue, correspond 

 in direction to the 2 semilunar incisions on the pedal disc 

 previously mentioned. 



The tentacles are placed in two series. 24 in each. 

 The\ are retractile, thick, and about half the leugth of 

 the breadth of the oral disc. The innermost series occu- 

 pies the periphery of the oral disc. and these are a little 

 longer than those that form the outermost series, and 

 that are placed on the uppermost margin of the body, 

 which is not capable of being drawn over the oral disc 

 (Pl. I, rig. 3. pl. VII. rig. (3). When the animal is con- 

 tracted it forms a smooth hemisphere whose arch is formed 

 by the oral disc. 



The exterior wall of the body is, as usual, clad with an 

 ectoderm consisting of long cylinder-cells, furnished with 

 ciliæiPl. VII, rig. 9 a) and between which oblong unicellular 

 mucous-glands are observed. In the rather broad connective- 

 tissue laver well developed circular muscle-fibres are seen. 

 (Pl. VII. rig. ',1 c) which lie closer to the endodermal than 

 to the ectodermal side: so that between the endoderm and 

 the muscle-fibres there is onlv a narrow belt of the con- 

 nective-tissue laver, whilst it is verv broad towards the 

 ectoderm. and in this broad part connective-tissue corpus- 

 eles with one or more prolongations are observed (Pl. VII, 

 rig. 9 6). On the inner surface of the connective-tissue, 



