LUMINOUS ANIMALS 145 
be present either below the eyes or on the 
body. 
Luminosity among the crustaceans is fairly 
common. Some of the deep-sea crabs possess 
phosphorescent eyes, the tips of which shine 
like balls of fire. A South American species 
(Cancer fulgens), discovered by Sir Joseph 
Banks, is so luminous that, according to Mr. 
Holder: “ Its entire surface seemed bathed 
with a white flame, that flashed and sparkled 
like living fire, and so resembled it that later 
one of the sailors picked the crab up, thinking 
it a coal that had rolled out of the galley 
fire.” 
Certain species of shrimps and prawns are 
endowed with the power to emit light, several 
of them being found in British waters. In 
some kinds the light-producing organs are 
situated at the base of the antennse, while in 
others a large number of luminous points are 
distributed all over the body. One species 
(Nyctiphanes norvegica), found around the 
coasts of Great Britain, possesses light-giving 
organs situated upon the thorax and abdomen, 
and if some of these creatures be put in a glass 
bowl full of water in a darkened room, they 
appear like flashes of light as they dart about 
from side to side of the vessel. 
Another tiny crustacean, called Metridia 
K 
