259 
Aeginura Grimaldii Maas is still more widely distributed in 
Oceamc depths, being known (under different names, see below, 
p. 2/6) from the northern Atlantic, the tropical Atlantic, the Indian 
Ocean, the Malayan Archipelago, the eastern tropical Pacific and 
the Bering Sea (Bigelow 1913), alltogether in deep water. — In 
the Davis Strait it was found at four stations from 60° 07' to 
64° 06' n. Lat. with 1200—2000 m. wire. 
None of these species are known from the Antarctic area. 
Pantachogon rubrum Vanhoffen, possibly identical with P. 
Haeckehi Maas from the Irminger Sea and Spitzbergen. P. rubrum 
is known from deep water in the tropical Atlantic, the tropical Indian 
Ocean, the Malayan Archipelago, and the Antarctic Ocean, being 
found abundantly in the area south of Africa between 55V 2 0 and 
64° s. Lat. (it must be remembered that the Southern point of 
Africa is at 35° s. Lat.). - The “Tjalfe” has taken the same 
species in the deep Davis Strait from about 60° to 64° n. Lat. 
Maas, in some of his excellent works on medusæ, has dealt 
\uth the problem of “bipolarity” as regards the medusæ, and he 
States (in “Fauna arctica” 1906) that among the holoplanctonic 
medusæ no species at all are common both to the northern and 
the Southern Polar area, but a few genera are. As to the 
deep-sea medusæ, particularly, he finds that some species are 
common to the tropical Oceanic depths and one or the other Polar 
area, but no species is common to all the three regions; thus, 
in the medusæ we find a well marked “unipolarity.” As especi- 
aHy instruct ive he notes the three species of Periphylla, dode- 
cabostrycha being known hitherto only from the tropical Oceanic 
depths, widely distributed towards east and west, reginq from the 
tropical depths of the Pacific and the Atlantic and from the Ant¬ 
arctic, and hyacinthina from the tropical depths of the Indian Ocean 
and the Atlantic and from the arctic and northern Atlantic._Now, 
Pantachogon rubrum has been found in the depths of the tropical, 
the antarctic and the arctic Atlantic areas. It is true, it must 
be admitted that the depths of the Davis Strait are not arctic, the 
17* 
