8o PELAGIC FAUNA 



In the China Sea, at a depth of between 3,400 and 3,800 metres, we 

 found a third species. This is much larger than the others, being 25 centi- 

 metres in diameter, and is a pale, translucent blue with light-brown 

 tentacles, Fig. p. 89). Also at this position we found an altogether new 

 type, quite unrelated to the rest. It has been described as a new genus, 

 Galatheathuria (Fig. p. 90 above). It is broad and oval in shape, is 22.5 

 centimetres long and 15 centimetres broad, and has a swimming fringe 

 along either side. Its colour is dark violet and its consistency when fresh 

 was rather firm. In the integument are numerous cruciform, calcareous 

 spicules. It was a sensational find. 



Many medusas belonging to the bathypelagic region have either a very 

 powerful musculature or are very thick and gelatinous. 



The two magnificent medusae, Atolla (Fig. p. 77) and Periphylla 

 (Fig. below), were taken in nearly all of our bathypelagic hauls. They 

 have vivid dark brown and dark bluish-violet colours, and both are wide- 

 spread in the ocean depths. Atolla is even found in the icy deep of the 

 Arctic Ocean, but is absent from the Mediterranean, being such a cha- 

 racteristically deep-sea species that it has never succeeded in crossing the 

 threshold of the Straits of Gibraltar. Periphylla, on the other hand, is 



The deep-sea medusa Periphylla, which 

 occurs in all the oceans. It can attain to a 

 diameter of 2§ centimetres. 



