76 



MEDUS.B. I. 



walls are destructed and detached from the subumbrella, only the narrow entodermal stripe, along 

 which the canal was attached to the snbumbrella, remaining. The sexual products are first evacuated 

 in the proximal part of the gonads, so that at a certain moment the radial canals are seen attached 

 to the subumbrella by the parts free of gonads and by the distal part of the gonadial part, from which 

 the sexual products are not yet evacuated, while the part, in which the evacuation has been completed, 

 hangs freely downwards like a bow (see the diagram, textfig. lo). Female individuals, which have evacu- 

 ated the eggs, are found to measure 40 — 56 mm in diameter; a male specimen, 44 mm wide, has spawned. 



Occurrence: 



The occurrence of Halopsis occllatn at the coast of North America is limited to the Gulf of 



Maine from Grand Manan to Cape Cod (A. Agassiz, Fewkes, Bigelow). 



The distribution on the European side of the North Atlantic is as follows: The species is 



common all along the south coast of Iceland, mainly in the neighbourhood of the coast. Hitherto it 



has not been found at the Faeroe Islands. It is common in the waters between Scotland and Rockall, 



and has been found, moreover, south-west of Ireland. As mentioned above, it has not previously been 



recorded from the European waters, thus all our knowledge of its occurrence in that area is based on 



the material here dealt with. It will be observed from chart IX, that it does not at any point surpass 



the Wyville Thomson ridge. As it has, besides, not been found 



at the western or northern coasts of Iceland, its distribution may 



be designated as being entirely Atlantic. The occurrence seems, 



moreover, to be mainly neritic. Thus during the cruise of the 



Fig 10 Haiop,,s oceUata A, .\gassiz. Dia- "Armauer Hansen" in 1913 the species was only found on stat. 



=ent°"^°^/exutbreut°"'pan?f t": ^7, the easternmost station of the expedition, above the deep 



frbee„%TacIt:?,-f;anof tleTo-S ^^^^""^1 ^^^ ^^ R^^^all, whereas :t was completely absent on all 



still containing sexual products, '• '' P™x- ^j ^j^^ westernmore Stations, 

 inial and distal parts of radial canal free oi 



gonads, St stomach. -^-^j^ regard to the bathymetrical distribution, the data at 



hand show that the species may be found at very different depths. — The specimens from the south 

 coast of Iceland have all been taken at a fairly short distance below the surface, in no case deeper 

 than about 40 m (with 70 m wire); some of the specimens have undoubtedly been found very close to 

 the surface. The specimens from Loc. No. 10, which is situated comparatively far south of Iceland, 

 were taken with 15 m wire, i. e. close by the surface. — West of Scotland, on the other hand, it has 

 been found, on certain occasions, in considerable depths, thus, for instance, by the "Michael Sars", 

 loc. a, with 1000 m wire. The various depths, in which the species has been found within that area, 

 will be seen from the following figures, representing the length of wire used by the hauls made: 50, 

 ^5i ^5) 15O) 200, 200, 300, and 1500 m, that means between about 30 and about 1000 m below the sur- 

 face. Of special interest is the station 17 of the "Armauer Hansen", where a specimen was taken in 

 a haul with 150 m wire out, whereas none were found in the deeper hauls (with 600, 1000, and 1300 m 

 wire). — South-west of Ireland i specimen was found in a haul with 200 m wire (loc. 15), and i spe- 

 cimen in a haul with 1500 m wire ("Michael Sars", loc. d). 



The very most of the finds have been made in the months of July and August. West of Scot- 



