157 



Forlegenhed. En Ting kan ansees som sikkert, og det er, 

 at de henhøre til den store Dyregruppe „Radiata". Der 

 er Intet, som tyder hen paa en bilateral Symetri, ikke 

 engang en Tendens til at menne sig denne er tilstede hos 

 de udviklede Dyr. imedens dug Embryonerne frembyde en 

 saadan. 



Der blev paa Expeditionen opsamlet ikke saa ganske 

 faa Exemplarer af begge Slægter; men de allerfleste vare 

 mere eller mindre ødelagte ved Skrabningen, saa jeg kun 

 havde et Par levende Exemplarer til Observation. Det 

 vårede næsten et Døgn, etter ;it de vare bragte i Observa- 

 tionskarret. førend Dyrene begyndte at røre paa sig ved 

 at udstrække Tentaklerne. Skibet rullede jo noget, saa 

 ganske roligt var der ikke i Karret ; men efter et Par 

 Dogns Forlob syntes Fenja mirabilis at være i fuld Vigør 

 og blev da tegnet og observeret. Ved denne Dndersøgelse 

 kom jeg forelobig til det Resultat, at jeg havde med en 

 Actinide at gjøre, og at det sandsynligvis var en Halcampa. 

 hvorfor jeg i min Notisebog opførte den midlertidig som 

 saadan. Lidt anderledes forholdt det sig med Ægir frigidus; 

 den var trægere i sine Bevægelser, udstrakte vel efter 

 længere Tid sine Tentakler, men syntes i det Hele tåget 

 ikke at befinde sig vel, da den jævnlig holdt sig tem- 

 melig meget kontrahent: Observationerne gik dog i den 

 bestemte Retning, at jeg ogsaa her havde for mig en Acti- 

 nide, der nærmest maatte henføres til Cerianthidcrne, og 

 som saadan blev den opført i min Notisebog. De i levende 

 Live observerede Exemplarer bleve omhyggelig konserverede 

 i Alkohol, og det er da disse, der væsentlig have tjent til 

 ilen mere detaillerede Undersøgelse. Af denne fremgaar 

 det da, at man her har for sig ret mærkelige Overgangs- 

 former, der ikke uden Vanskelighed kunne henføres til de 

 for Tiden opstillede Dvreafdelineer. 



Huden med dens Epithel, Nematocyster, Slimkjertler 

 og Bindevæv, Tentakelform, Septadannelse, Generations- 

 organer og Nervesystem, Alt er i den fuldkbmneste Over- 

 ensstemmelse med Ooelenteraternes Type; men det, der 

 dog er opstillet som Hovedkarakter for denne, nemlig 

 ., Gastro vascularhtdheden" mangler, eller er her omdannet 

 til en virkelig Kropshulhed (Coelom), samtidig med at 

 der er en fuldt udviklet Tarmkanal, som tager sin Begyn- 

 delse ved Munden og ender i en Anus. og som for Fenjas 

 Vedkommende ikke kommunicerer direkte med Kropshul- 

 heden, men denne er ved 12 fuldstændige Septa delt i 12 

 Længdekamre. 



Hos Slægten Ægir er der længst bag paa Reetum, 

 nogle Millimeter foran Anus. 12 fine. knapt en Millimeter 

 lange Spalter, hvorved Kropshulhedens Kamre staa i direkte 

 Kommunikation med Tarmhulheden. Her er et Forhold. 

 som ogsaa med Hensyn til Fordøielsesapparatet nærmer 

 sig noget Coelenteraterne, især Cteriophorerne. der som 

 bekjendt har et langt Svælgrør, der strækker sig næsten 

 gjennem Kroppens hele Længde, og som udmunder i de 

 laterale Gastrovascularrum med to trange Sidespalter. Men 

 hvad der dog udgjor en stor Forskjel, er den Omstændig- 



great dubiety. One thing may be considered as certain and 

 that is, that tliey belong to the great animal-group ,,Radiata". 

 There is nothing that points to a bilateral symmetry, 

 not even any tendency to it is apparent in the developed 

 animals, whilst the embryons, Innvever, present such an 

 indication. 



There were collected during the expedition not so 

 \ei\ tew speeimens of lioth genera, hut the greater number 

 were more or less injured by the dredge, so that I only 

 obtained a couple of animate speeimens for my investiga- 

 tions. It was nearly 24 hours after the animals had been 

 placed in the glass vessels before they began to show anima- 

 tion by extending the tentacles. The ship. it is true, rolled 

 a good deal, so that it was not altogether quiescent in the 

 glass jars. hut after a couple of days and nights Fenja 

 mirabilis appeared to be mi full vigour, and was then 

 drawn and observed. Upon this observation, I arrived at 

 . the preliminary conclusion, that I had to do with an Ac- 

 tinida, and that it was probably a Halcampa, for which 

 reason I entered it as such. temporarily, in my Note-Book. 

 The case was. however, a little different with Ægir frigidus; 

 it was more sluggish in its movements, and. although it 

 extended its tentacles after a. considerable time it did not 

 appear to be at all comfortable. as it generally kept itself 

 pretty much contracted; the observations. however, led in 

 the distinct direction that here. also. I had to do with 

 an Aetinida, which ought most properly to be assigned 

 to the Cerianthida, and as such. therefore, it was entered 

 in my Note-Book. The speeimens examined during lite 

 were carefully preserved in alcohol, and it is therefore 

 those that have principally served for mv subsequent, more 

 detailed investigations. From these it results that we have 

 here. very remarkable transition forms, which cannot, without 

 difficulty, be assigned to the present existent, established 

 animal divisions. 



The integument with its epithelium. nematocysts, muc- 

 ous glands and conuective-tissue, the tentacular form. septal 

 formation, reproductive organs and nervous system, are all 

 in perfect harmony with the Coelenterata type. hut the 

 feature which is, however. established as the chief charac- 

 teristic of that type viz. the gastro-vascular cavity, is awanting, 

 or is here transformed into a real body-cavity (Coelome), 

 whilst. at same time, there is a fully developed intestinal 

 canal. with its origin at the mouth and terniinating in an 

 anus that, in Fenja mirabilis, does not directly communicate 

 with the body-cavity, which is divided by 12 perfect septa 

 into 12 longitudinal chambers. 



In the genus Ægir there are at the extremity of 

 the reetum. a few millimetres in front of the anus. 12 

 niinute, scarcely a millimetre long, fissures, by which the 

 chambers of the the body-cavity are placed in direct com- 

 munication with the intestinal cavity, Here therefore, 

 we have a relation which. also. in respect of the digestive 

 apparatas approaches somewhat to that of the Coelen- 

 terata, especially to that of the Ctenophora, which. as is 

 well known. has a long gullet-tube extending almost the 

 whole length of the body and opening into the lateral 



