|a3 



MEDUSA. I. 



wrinkled. The tentacles seem to be fairly long, but owing to the state of preservation the exact length 

 cannot be stated. Between every successive pair of tentacles there are two (rarely one) appendages 

 which are, I think, homologous with the cordyli of the other Laodiceidce. These cordyli are cylindrical 

 or somewhat spindle-shaped, provided with a cluster of nematocysts in the distal end (Plate I, figs. 2 

 and 3); they are hollow and consist of a thin ectodermal epithelium and a thick entoderm of cubical 

 cells in a single layer, enclosing a central lumen, which communicates with the circular vessel. The 

 cordyli are translucent and colourless. — The velum is thin and narrow. 



The colour of the manubrium, tlie radial canals, the circular vessel, and the tentacles is brightly 

 orange or brick-red; moreover the tentacular bulbs contain a brownish entodermal ijigment-mass. The 

 gonadial sacks are white. 



Dimensions. — The largest specimen, which I have seen ("Michael Sars" Stat. 84, 1910), is about 

 27 mm in diameter and about 22 mm high; it has about 24 tentacles and about 16 gonads on either 

 side of each of the radial canals. In the Davis-Strait the species does not seem to grow to such large 

 dimensions, the largest specimen from that area, a fully mature female individual ("Tjalfe" St. 336), being 

 17 mm wide, 14 mm high, with 18 tentacles, and with 13 — 14 gonads on either side of each radial 

 canal. A male specimen from the Irminger Sea ("Thor" Stat. 180, 1904) shows the following dimensions: 

 diameter 14 mm, height 12 mm, length of the gonadial part of the radial canals 6 mm, breadth of the 

 same 2' 2 mm, length of the distal narrow part of the radial canals 3^/2 mm, 12 pairs of gonads on 

 each radial canal, number of tentacles not stated. 



Distribution. — Widely distributed in the deep parts of the northern Atlantic north of about 

 40° N. Towards the North the distribution is limited by the submarine ridge Scotland — Faeroe Is- 

 lands— Iceland— Greenland— Baffin Land. The northernmost locality is: Lat. 65° N., Long. 54° W. (Mol- 

 ler), southernmost: Lat. 39° 52' N., Long. 69° 45' W., westernmost: Lat. 39° 57' N., Long. 70° 15' W., eastern- 

 most: Lat. 61° 15' N., Long. 9° 35' W. 



Bathy metrical Distribution. — The species occurs almost exclusively in the deeper strata. 

 Most specimens have been caught with instruments for pelagical fishing with 1000—3000 m wire out, 

 i. e. about 600—2000 m below the surface. During the Atlantic expedition of the "Michael Sars" in 

 1910, however, a specimen was taken by a haul with 100 m wire (stat. 81, Lat. 48° 02' N., Long. 39° 

 55' W.), and in one case the species has even been taken with a hand-net at the surface, viz. off the 

 west-coast of Greenland by H. P. C. M oiler (see below). 



The first published description and figure of this medusa were given by Fewkes (1882). But 

 the species has been figured and described many years before, though that figure as well as the de- 

 scription seems to have disappeared. 



In the Zoological Museum of the University of Copenhagen I ha\e found a specimen, collected 

 by H. P. C. Moller off the west-coast of Greenland. Though only slight traces of the gastrogenital 

 organs are left, these slight traces in connection with the tentacles, which are fairly well preserved, 

 partly expanded, and the entire shape of the medusa, with its very thick gelatinous substance, put it 

 beyond doubt that the specimen must be referred to the species Chroiiiatoucvia mbniin. The specimen 

 was in a glass-tube with a label of the content shown on p. 10. The Zoological Museum possesses a large 

 number of notes and drawings made by H. P. C. Moller, who was inspector in Greenland for some 



The Ingolf-Expedition. V. 8. 2 



