. Il danese Ingolf-spedizione. Animali marini -- regioni artiche; spedizioni scientifiche; regioni artiche. MEDUSjE III 43 6. 30° 80' ?0' III' così 'w' 30V0'10° 0" 10' ^0° 30° *0° 50" iO" 70° 3 30'. Fii;. 16. Distributinii nell'Atlantico iinitlifrii di Periphylla periphylla. 0 nuovi record; ? I record precedenti, esemplari in Zoolosical .Muscnni, Copenliasen; q altro previons record. regioni. In un documento precedente (l'Jl3;i) ho sottolineato che in stretto di Davis i giovani esemplari sono particuhirly abbondanti negli strati profondi, mentre Stiasny (1934 p. 363) è del parere che il piccolo io
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. The Danish Ingolf-expedition. Marine animals -- Arctic regions; Scientific expeditions; Arctic regions. MEDUSjE III 43 6. 30° 80' ?0' iil' SO' w' 30V0'10° 0" 10' ^0° 30° *0° 50" iO" 70° 3 30'. Fii;. 16. Distributinii in the iinitlifrii Atlantic of Periphylla periphylla. 0 new records; ? previous records, specimens in Zoolosical .Muscnni, Copenliasen; Q other previons records. regions. In a previous paper (l'Jl3;i) I pointed out that in Davis Strait the young specimens are particuhirly abundant in the deep strata, whereas Stiasny (1934 p. 363) is of the opinion that the small individuals mainly occur at higher levels than the large ones, and this opinion was based partly upon his own examina- tion of the "Discover}'"' collections, partly on the .statements by Broch in the "Michael liars'' report (1914). I have measured the diameter of all the specimens taken liy the "Dana"; in the collections from the older expeditions the specimens were picked out and preserved more or less at random, and these collections are therefore not representative and are not con.sidered in the following calculations. The results of the measure- ments are given in Tables V-VII, and for comparison I have summarized the results from other geographical areas as obtained liy iStiasny, Broch, and my.self in Tables I-IV. The results are not directly comparable, because the diameter of the medusae has been measured in different ways by the various authors. The diameter of the "Dana" specimens is measured to the base of the marginal lappets; Broch ])referred to measure the diametei- of the central disk above the annular furrow. None of these metiiods are quite reliable, because the shape of the inodusa is very variahh' according to the state of contraction, and this a|)plies not iner(>ly to the bell margin, but to the gelatinous central disk as well. Nevertheless, in spite of the unavoidable incorrectness of the measurements, they give an
