Y. HANEDA 345 



probably luminous, the light of these specimens was not actually 

 observed. 



In my own observations, luminous jellyfish appear abundantly 

 along the coast of Japan, especially from March to June. About the 

 end of April, 1953, I collected many luminous Pelagia in a flying fish 

 net near Hachijo Island, and in May of the same year observed 

 luminous Pclagiu in great numbers in Yokosuka harbor and along 

 the west coast of Izu Peninsula. 



In the flying fish nets at Hachijo Island, many luminous Ctenophora 

 such as Beroe and Cesttim are caught. In June, 1953, along the coast 

 of Namerikawa, Toyama Bay, numerous Beroe are often mixed with 

 luminous squid, Wotasenia scintillans, the whole net becoming bril- 

 liantly luminous. Several species of Siphonophora, such as Fraija, 

 Diphes, and Abyla, which were caught in a plankton net at Aigae 

 Bay, Hachijo Island, were also observed emitting light. 



In May, 1953, I collected Aequorea sp. by trawl net in Suruga Bay. 

 This is a rather large Medusa, 200 mm in diameter, which emits a 

 flash of light on irritation. 



In September, 1943, in the sea around the Thousand Islands, coral 

 islands off Jakarta, Java, species of Ctenophora which emitted a 

 flash of light when irritated were found. 



Observations by Undersea Observation Chamber 



Twice I have had the opportunity of observing luminous organisms 

 in the sea at night while riding in an undersea observation chamber, 

 called "Ktirosliw' (Inoue, Sasaki, and Oaki, 1952, 1953). 



The observation chamber was 3.15 meters in height, 1.48 meters in 

 diameter, and weighed from 4440 to 5220 kg, with a buoyancy of 

 from 4192 to 4297 kg. The chamber had a main observation window 

 (150 mm diameter) with controllable reflector, 3 auxiliary observa- 

 tion windows ( 100 mm diameter ) , telephone, teletalk, oxygen feeder, 

 CO2 absorbing unit, projector lamps and miscellaneous gages. The 

 Kuroshio observation chamber was hung down along the outside of 

 the hull of the mother ship by means of a steel wire pulley on the end 

 of a derrick. The lowering and raising was done by an electric motor 

 winch, usually at a speed of about 20 meters per minute. 



In all, 130 diving observations were made in 1952 along the Japan 



