MEDUSAE. I. 



The depth in which the individuals have been captured is only stated in very few cases. Some 

 of the specimens from Iceland are fished with 70 80 m wire out; on "Thor" stat. 259(04) three hauls 

 were made with the young-fish trawl; the journal records as follows: 20 m wire: "yellow-rayed medusa"; 

 35 m wire: about 20 do.; 70 m wire: about 20 do. The depth of the bottom was 102 m, and Melicertuin 

 lias been evenly numerous at least in the upper fifty meters. Undoubtedly it does not penetrate down 

 into any great depth; it may be met with, on the other hand, close to the surface. 



The horizontal distribution, it will be seen, is rather narrowly limited. The species has never 

 been found in high-arctic regions, and it does not, on the other hand, penetrate very far southwards. 

 It is indigenous at the northern coasts of the British Isles, but only occasionally it is carried towards 

 the Channel. It is very noticeable that most of the Icelandic localities are crowded around Cape 

 Langeuaes, the north-eastern point of Iceland. This seems to be more than a casuality and it may 

 possibly be explained by the fact, that the Polar Current strikes the coast of Iceland at this point 

 and puts a stop to the effects of the Irminger Current (that branch of the Gulf Stream which runs 

 northwards along the west coast and eastwards along the north coast of Iceland). It is hardly possible 

 that the numerous individuals of Melicertum, found around Langenaes in July and August 1904, may 

 have been carried to the Icelandic coast by the Polar Current ; most probably they have been hatched 

 at the west or north coast of Iceland and carried eastwards by the Irminger Current as far as Lange- 

 naes, where they have come to a stop, because the cold water of the Polar Current barred the pas- 

 sage. At the Norwegian coast the species is numerous off the part between Stavanger and Stat. 

 It has frequently been found iu the Danish waters, but never in any large number, so that this 

 area is possibly beyond the proper area of distribution of the species. The fact is, probably, that the 

 polyp generation does not live at the Danish coasts and the southern parts of the British coasts, but 

 that the medusa is usually carried to these regions in the summer. In order to elucidate this question 

 more thoroughly we shall have to look at the seasons, in which the species has been found on the 

 various localities. 



All the Icelandic collections have been made during the summer months; we have no informa- 

 tion from the other seasons of the year. The finds from the north-east point are from the time between 

 July 2oth and August 3oth. 



The specimens from West-Norway, mentioned by Broch, as well as the specimens from Ber- 

 gen, recorded in the present paper, have all been taken in July and August. More interesting is the 

 statement of Sars, that the species occurs at the Flor0 from the early spring to September. 



We possess several and detailed records of the occurrence at the British Isles, but it is not 

 very easy to get a reliable apprehension of the occurrence in that area. Most statements agree that 

 the species appears in the Scottish fjords in the month of May and is numerous during the summer 

 months. Browne (1905) states that it occurred in the Firth of Clyde from May 2oth to October nth 

 1902, grown-up specimens in May, grown-up as well as young specimens in July; besides many grown- 

 up individuals were found at Arran in August 1897. According to Me In tosh (1890), on the other 

 hand, it appeared at St. Andrews in August; it was numerous in October but not yet mature; large 

 specimens were found in December; he also found it at St. Andrews in January, and Crawford (1891) like- 

 wise found a mature specimen in January at the same locality. All records being kept together, it seems 



