56 



brunligt. Tentaklerne ere sædvanlig noget brunagtige i 

 deres ydre fligede Del; Mundskiven var hos enkelte Indi- 

 vider lys græsgrønlig. Generationsorganerne skinne ved 

 deres gulhvide Farve igjennem Kroppens transparente Hud. 



Medens de nærmest beslægtede af vore norske Holo- 

 thurider, nemlig Synapta inhærens og Chirodota pellucida, 

 begge leve nær ved Stranden, fra Lavvandsmærket indtil 

 10, sjeldent 20 Favne, har jeg altid fundet den her be- 

 skrevne, ligesom en tredie rorsk Art, Synapta tenera Nor- 

 man, paa dybt Vand, 50—200 Favne, dyndet eller blød 

 Lerbund, hidtil kun paa faa Localiteter, ved Drøbak i Chri- 

 stianiafjorden (Storemedet tæt ved Byen og lige ud for et 

 Teglværk J Mil sydligere) paa 50—60 F., Rødtangdybet, 

 100- 120 F., og ved Vallø paa 200 F. Den lever her ned- 

 graven i det bløde Dynd, men er idethele sjelden. Endelig 

 har min Søn fundet den ved Skraaven i Lofoten lige ned 

 til 300 F. Huden sprækker hos de fleste Exemplarer, naar 

 man faar dem op og ikke haandterer dem med den største 

 Varsomhed, tværsover den forreste Del af Kroppen, saa at 

 Hovedet, om man saa kan kalde det, d. e. Mundpartiet med 

 Tentakelkrandsen og Halsen med Svælget og Svælgringen, 

 afløser sig fra den øvrige Krop og Tarm. Synapta inhæ- 

 rens bryder sig derimod ved transversale Indsnøringer nær 

 ved den bageste Ende af Kroppen og successive længere 

 fortil i et større eller mindre Antal af Tværstykker, og Chi- 

 rodota pellucida sprækker næsten aldrig. 



Efter den meddelte Beskrivelse er det klart, at nær- 

 værende Holoth uride staar nærmest ved Slægten Myriotro- 

 chus Steenstrup og, ligesom denne, er den sandsynlig en 

 arktisk, med flere andre høinordiske Dyr paa de anførte 

 Localiteter i Christianiafjorden igjenlevende Form. Den 

 viser sig i de fleste Henseender, og navnlig i den mange- 

 straalede Form af dens Kalkhjul og deri, at disse ere en- 

 keltvis stillede, ikke indesluttede gruppevis i en Blære, saa 

 overensstemmende med den nævnte Slægt, at man kunde 

 være fristet til at opføre den som en anden Art af denne. 

 Imidlertid er der dog, som allerede ovenfor paavist, nogle 

 Punkter i dens Bygning, hvilke synes at gjøre en generisk 

 Adskillelse fornøden. Først nemlig den næsten fuldkomne 

 Mangel af Kalkafleiringer i Huden, idet der kun i den for- 

 reste og bageste Del af Kroppens Hud finder, et meget 

 ringe Antal af mikroskopiske Kalkhjul, medens disse hos 

 Myriotrochus findes i stor Mængde over den hele Krop. 

 Dernæst, at disse Kalkhjul ligge indsænkede i Kroppens 

 Hud, hos Myriotrochus derimod ragende frem over dens 

 Overflade baarne paa Hudstilke. Endelig, at Hjulene i Re- 

 gelen have et ringere Antal af Straaler og at disse ikke, 

 saaledes som hos Myriotrochus, i Antal svare til Ringenes 

 Stykker eller disses Tænder. 



Ogsaa i Tentaklernes Form synes der at være 

 nogen Forskjel, idet de hos vort Dyr mere ligne Synapta 

 derved, at de ere trinde, conisk-tilspidsede og i deres 

 ydre Del besatte med fingerförmige Grene paa begge 



extremity went over to a light red or brown. The tentacles 

 are usually somewhat brownish in their outer lobed part; 

 the oral disc was in some specimens light grass-green. 

 The organs of generation shine yellowish white through 

 the transparent skin of the body. 



While the nearest related of our Norwegian Holothu- 

 ridæ, namely the Synapta inhærens and Chirodota pellucida, 

 both live near the shore, from low-watermark to 10, seldom 

 20 fathoms, I have always found the species here described, 

 as also a third Norwegian species viz. Synapta tenera Nor- 

 man, in deep water 59 — 200 fathoms, on miry or soft clay 

 bottom, hitherto only in few localities: at Drøbak in the 

 Christianiafjord (Storemedet close to the town, and just 

 off some tile-works \ mile more to the south) in 50 — 60 

 fathoms; in Rødtang-deep 100 — 120 fathoms, and at Vallø 

 in 200 fathoms. It lives here buried in the soft mire, but 

 is on the whole rare. Finally my Son has found it at Skraa- 

 ven in Lofoten even at the depth of 300 fathoms. In most 

 specimens, if when the animal is drawn up, it is not handled 

 with the greatest care, the skin bursts across the anterior 

 part of the body; so that the head, if one may call it so, 

 that is the oral part with the circle of tentacles, and the 

 throat with the gullet and calcarous ring — separates itself 

 from the rest of the body and the intestine. Synapta 

 inhærens on the other hand, breaks by transversal instric- 

 tions near to the posterior part of the body and succes- 

 sively further forwards, into a greater or less number of 

 transverse fragments; and the Chirodota pellucida scar- 

 cely ever breaks at all. 



According to the description here communicated, it is 

 evident that the present Holothurian stands nearest to the 

 genus Myriotrochus Steenstrup; and like the latter it is 

 probably an arctic form surviving in the Christianiafjord 

 with many other animals belonging to high latitudes. Ii 

 shews in most respects, particularly in the many-rayed form 

 of its calcarous wheels and in these wheels being placed 

 singly, not enveloped group wise in a vesicle — so much 

 conformity with the genus mentioned, that one might be 

 tempted to class it as another species of the same genus. 

 There are however, as already previously shewn, some 

 points in its structure which appear to require a generic 

 distinction. First namely, the almost total absence of cal- 

 careous deposits in the skin; only a very small number of 

 microscopic calcareous wheels being found in the anterior 

 and posterior part of the skin of the body and none else- 

 where; while in the Myriotrochus on the contrary they are 

 found in great numbers over the whole body. Next, that 

 these calcareous wheels lie sunk in the skin of the body, 

 while in the Myriotrochus they project above its surface 

 supported on skin-stalks. Finally, that the wheels have 

 usually a smaller number of rays, which moreover do not, 

 as in the Myriotrochus, correspond in number with the 

 pieces of the ring or with its teeth. 



Also in the form of the tentacles there appeares to be 

 some difference; the tentacle of our animal being more 

 like those of the Synapta, round, conically pointed and in 

 their outer part furnished with finger-like branches on both 



