BY CRAB-LIGHT. 75 



phire, purple, green, and other hues — appear in bewildering 

 frequency, ranging from the softest to the most intense and 

 vivid lights, marking this living sapphire as one of the true 

 gems of the sea. 



Giglioli mentions an Isopod crab, brilliant with gold antl 

 purple, gorgeous with iridescence, and possessed also of the 

 additional charm of phosphorescence- The light-emitting 

 organs in the Entomostracans observed by him were in the 

 anterior portion of the thorax. 



The young (Zoea) of the graceful little opossum shrimp 

 Mysis stenolepis is phosphorescent. The adult forms are 

 extremely interesting objects for study, the eggs and young 

 being carried in a little pouch beneath the thorax. Allied 

 to this little sea-opossum is Lucifer, that is to the crustaceans 

 what the walking-stick is to the insect world ; a veritable 

 incongruity, resembling a branch of weed, and doubtless 

 finding some protection in the mimicry. Some specimens, 

 according to Giglioli, are luminous ; the gift perhaps forming 

 a signal language, a code understood in this world under the 

 sea. The position, or seat, of the luminosity in crustaceans 

 differs as widely as the intensity and color of the light ; and 

 in the little ■ Stomatopod, formerly considered as an adult, 

 and described as Squillerichthus, we find the culmination of 

 wonders, as, in a specimen of this genus found in the Atlantic, 

 the seat of the brilliant intermittent yellowish-green light is 

 in the eye-stalk ; so that the eyes themselves may be said 

 to be veritable lanterns. 



The phosphorescence of crabs was probably observed for 

 the first time by Sir Joseph Banks, on his voyage from 

 Madeira to Rio Janeiro ; a small crab, named Cancer fulgens, 

 being captured, which was remarkably luminous. Sir Joseph 



