LIVING LAMPS 235 



steady and continuous light. Mr. Alexander Agassiz wrote 

 that in the Gulf of Mexico he found a salp chain far exceeding 

 in size any of those known before — a huge band several yards 

 in length and a foot in breadth, which at night, when seen 

 from the deck, seemed like a huge veil of bright greenish phos- 

 phorescence. He noted that one of the smaller kinds of salps 

 gives out generally a bluish light. 



The tunicate called Doliolum gives off a greenish light, and 

 some of those curious things called appendicularians shine 

 very brightly, reddish, white or green. 



Very many of the small crustaceans give out a brilliant flash, 

 from almost white to greenish or bright blue in color, and some 

 are luminous even in the earliest stages. Many of the little 

 copepods are very bright, but the most surprising things of 

 all are the little ostracods abundant in some places in the east, 

 an example of which is the Japanese "sea fire-fly." It is al- 

 most unbelievable these little things can produce the amount 

 of light they actually do. Some of the schizopods have long 

 been famous for their brilliancy, and there are other luminous 

 oceanic types with various sorts of light organs differently dis- 

 tributed, sometimes in their eyes. 



Many of the larger bottom living deep sea crustaceans give 

 off copious clouds of a ghostly blue light from near the bases 

 of the antennae or the eyes, sometimes from other places. 



Most of the luminous crustaceans live in the open ocean or 

 on the bottom at great depths; there are very few along the 

 shores. 



Luminous sand-hoppers or beach-fleas are sometimes seen. 

 These animals are not really luminous, but they are affected 

 with a luminous disease caused by bacteria which gives off a 

 steady greenish light. 



Occasionally the dredge brings up non-luminous crabs or 

 hermit crabs with dense tufts of luminous plant-Hke animals 

 growing upon them. 



Some of the pycnogonids are brightly phosphorescent. 

 Lieut.-Col, Alcock mentions one dredged off the east coast of 



