31 



slyngede, tabe deres Kontraktionsevne, idet de i udstrakt 

 Tilstand blive hængende langs Kroppens Overflade, Tab. X, 

 Fig. 4. Kroppens øverste Rand er tentakulær. 



Mundskiven er lidt hvælvet og rigt foldet; Polderne 

 udstraale vifteformigt fra Munden, ere overalt rigt for- 

 synede med Cinclides, hvorigjennera Acontier udslynges. 

 Disse ere i stor Mængde tilstede paa den l>el af Skiven, 

 der nærmest omgiver Mundaabningen. Denne er aflang 

 og har en bred Gonidiegrube med to smaa G-onidieknuder 

 paa liver Side. Mundlæberne ere sexlappede, hvorved 

 Mundaabningen faar Udseende af at være omgiven af en 

 Krands, Tab. III. Fig. 1. 2. 



Tentaklerne ere meget lange og staa i 3 Rækker; i 

 den indre er der 12, som ere de længste og meget» 

 hengere end Mundskivens Bredde ; i den mellemste Række 

 er 24, der ere meget kortere, end de indre, og i den 

 vd re Række, som indtager Kroppens øverste Rand, er der 

 ligeledes 24, af omtrent samme Længde og Tykkelse som 

 de i 2'len Række. Tentaklerne ere retraktile, og saavel 

 disse som Mundskiven kunne ganske skjules af Kroppens 

 øverste Rand. naar Dyret kontraherer sig, Tab. X, Fig. 4. 



Farven. Skeden er brun; Kroppens Hud er rosen- 

 rød med blaalige Længdestriber , men dens øverste Rand 

 er næsten kastaniebrun. Mundskiven er smuk rødbrun ; 

 Læberne bleg rosenrøde, G-onidiefurerne blegere. De 

 indre Tentakler ere mørk kastaniebrune ; de mellemste 

 ere lysere, og de ydre ere laxerøde ; f o ro v rigt varierer 

 Farven ganske betydeligt hos Individer fra forskjellige 

 Lokaliteter, fra hvide til rode. ja næsten brune over det 

 Hele. 



Ved den mikroskopiske Undersøgelse viser paa Tver- 

 snit den omtalte Overhud sig at beståa kun af Ler, fin 

 Sand og Slim; ingen histologisk Bygning tindes i den. Ei- 

 den fjernet, sees det sædvanlige Eetoderm, bestaaende af 

 lange, eilierende Cylinderceller, encellede Slimkjertler og 

 Neiuatocyster, Tab. X, Fig. 5 a, 6 a. Indenfor Ectodermet 

 er et temmelig smalt, fibrillært Bindevæv, hvori sees for- 

 uden Bindevævslegemer og fine Ernæringskanaler, cirkulære 

 Muskler, som indtage omtrent Midtpartiet af Bindevævs- 

 laget, dog nærmere Ectodermet, Tab. X, Fig. 5 b. 6 b, ja 

 paa enkelte Tversnit ser det ud, som om disse Muskler 

 lægge sig lige hen til Ectodermet. De ligge neppe i 

 Bundter; det synes snarere, som hver Fibrille er isoleret. 

 Paa Længdesnit sees imidlertid, at Fibrillerne ligge tæt 

 til og paa hverandre og synes at anastomosere med hin- 

 anden. Tab. X, Fig. 5 b. 



Der er 6 Par principale, fuldstændige Septa, hvoraf 

 2 Par ere Retningssepta. Disse ere temmelig iøinefaldende 

 derved, at de ere meget vide. det vil sige, at det intrasep- 



as if nianv acontia after being projected, lose their power 

 of contracting, as they remain pendulous, in the extended 

 condition, along the external surface of the body (Pl. X, 

 fig. 4i. The uppermost margin of the body is tentaeular. 



The oral disc is a little arcuate aud richlv folded. 

 The folds radiate in flabelliform, from the mouth, and 

 are everywhere richlv furnished with cinclides through 

 which acontia are projected. These are present in great 

 abundance on the portion of the disc. which in closest 

 proximity surrounds the oral aperture. This is oblong, aud 

 has a broad gonidial groove with two small gonidial knobs 

 on each side. The oral labiæ are six-lobate, which gives 

 to the oral aperture the appearanec of being surrounded 

 by a wreatli (Pl. III. fig. 1, 2). 



The tentacles are very long, and are placed in 3 

 series; in the iniiermost series there are 12 tentacles and 

 these are the longest, being much longer than the breadth 

 of the oral disc; in the interinediate series there are 24 

 tentacles, which are much shorter than those of the inner 

 series; and in the outer series, which occupies the upper- 

 most margin of the body, there are likewise 24. of about 

 the same leugth and tliickness as those of the 2nd series. 

 The tentacles are retractile, and both these and the oral 

 disc niay be completely concealed by the uppermost 

 margin of the body when the animal contracts itself 

 (Pl. X. fig. 4i. 



The colour. The sheath is brown; the integument of 

 the body is rosy-red, with bluish Longitudinal stripes, but 

 its uppermost margin is almost chestnut-brown ; the oral 

 disc is bea.utiful reddish-brown ; the labiæ are pale rose- 

 red with the gonidial grooves paler in colour; the inner- 

 most tentacles are dark chestnut-brown. the interinediate 

 are lighter in colour. and the outer ones salmon-red. The 

 colour varies however, quite considerably in individuals 

 from different localities, from white to red, even almost 

 to brown over the whole animal. 



Upon microscopical examination of transversal sections, 

 the external integument spoken of, shows itself to consist 

 of clay, fine sand and slime only ; no histological structure 

 is found in it. When it is removed the usual eetoderm 

 is found, consisting of long, eiliating cylinder-cells, unicel- 

 lular mucous-glands and nematocysts (Pl. X, fig. 5 fl, 6 a). 

 Inside of the eetoderm, there is a rather narrow, fibrillar 

 connective-tissue in which, besides connective-tissue cor- 

 puscles and tine nutritory ducts, circular muscles are also 

 found occupying the niesial portion, nearly, of the layer of 

 connective-tissue, but lying closest to the eetoderm (Pl. X, 

 fig. 5 b, Li ln. indeed in some transversal sections it ap- 

 pears as if these muscles lav themselves close in to the 

 eetoderm. They scarcely lie in fasciculi, but appear rather 

 as if each fibril was isolated. In longitudinal sections it is, 

 however. apparent, that the fibrils lie close to and upon 

 each other, and appear. as it were, to anastomose with 

 each other (Pl. X, fig. 5 b). 



There are 6 pairs of prineipal, perfect septa, of 

 which 2 pairs are directive septa. These are rather pro- 

 minent, owing to there being very wide, that is to say, 



