MEDUSA. I. 



13 



Though the species lias, mainly, a bathypelagical occurrence, it may, however, occasionally rise 

 to the upper water layers. On "Michael Sars" stat. 81 a specimen was fished by the ringtrawl with 

 100 ni wire in water of a fairly high temperature (about 13° C). 



More astonishing is the find, made by Moller, off the west coast of Greenland (see above, 

 p. 9). It is a well-known fact that oceanic deep-sea organisms are occasionally carried towards the 

 west coast of Norway and found there near the shore and in the upper water layers. Similar pheno- 



Chart I. Occurrence of Chromatoncma rubriim Fewkes in the northern .Atlantic. 



mena have been observed on the west coast of Greenland, and this may account for the appearance 

 of this oceanic deep-sea medusa comparatively near the coast and swimming at the surface of the water. 



The hydroid stage is unknown, and no young stage of the medusa has been observed; it is 

 impossible, therefore, to state, or even to guess, anything with regard to the development of the species. 



Related Species. — Bigelow (1909) has described a similar medusa from the eastern tropi- 

 cal Pacific (the Humbolt-Current off the coast of Peru, in intermediate strata). He called it Ptychogfna 

 erythrogonon. Bigelow possessed a series of specimens in different stages of growth, the largest being 

 38 mm in diameter by 25 mm high. The general appearance of the species bears a striking resem- 



