. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. â¢Hi ;M III. Kic. 7. Distnbiicion in the northern Atlantic of Pantachogon haeckeli 0 new records; Q previous records; (g) records not yet published. The statocysts are very small, each of them containing one Htatolith (PI. I'l fics. 7 s)." I have particularly looked for young which might jjive information of the development of the tentacles, but they were almast all in a very bad state of preservation. I .shall com- municate the few obser\'ations which I able
. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. â¢Hi ;M III. Kic. 7. Distnbiicion in the northern Atlantic of Pantachogon haeckeli 0 new records; Q previous records; (g) records not yet published. The statocysts are very small, each of them containing one Htatolith (PI. I'l fics. 7 s)." I have particularly looked for young which might jjive information of the development of the tentacles, but they were almast all in a very bad state of preservation. I .shall com- municate the few obser\'ations which I able to make. In a specimen only 2 mm high there are 2 tentacles and one intcrradial statocyst between every successive pair of radial canals, except in one octant, where there is one, interradial, tentacle and a statocyst close beside it. In a few specimens 3 mm high there are 3 tentacles between the radial canals, but it cannot be decided which of them the youngest. When the height of the bell is â 1-4* , mm, the number of tentacles between the canals usually .Meems to be 5, but in some cases the middle one (the interradial) is only a tiny rudiment. In one specimen, 5 mm high, there are fi tentacles between the canals, all alike, and in three of the octants there is a tiny rudiment of the seventh, final tontarle, and then always the third one from the left. In the course â elopment of the tentacles PauUichoynn haeckdi thus r< - to iliflcr from Coloboncma nericeuw, in wliich an interradial tentacle does not appear until four other tentacles have been developed. IJi(; ( p. 115) has found that "a tentacle does not al'-- -a canal, , it appears that in """ ilied as strictly perradial". I have â iirerteti niy attention this .statement and found that only on very rare occasions the tentacle nearest to a radial canal i^ not exactly opposite to if, and if it happens exceptionally, It 'leems t be off one of the canals (which
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Keywords: ., bookcentury1800, bookdecade1890, booksu, booksubjectarcticregions
