THE AETHROPODA OF THE DEEP SEA 133 



for life of the shallow water of the tropics ever since 

 the Lower Oolite epoch ; while Scalpellum, on the 

 other hand, has either become profoundly modified, 

 or been driven into the abysmal depths of the ocean. 



The group of the Thoracostraca, or stalk-eyed 

 Crustacea, including lobsters, crabs, hermit crabs, 

 prawns, and shrimps, is well represented in the deep 

 sea. Most of them are characterised by being quite 

 blind (in many cases even the eye-stalks are oblite- 

 rated), by being protected with a dense covering of 

 spines, by the thinness of their shells, and by their 

 bright red or carmine colour. 



The order Stomatopoda is almost entirely confined 

 to the shallow waters of the tropical or temperate 

 shores. Not a single species is known to inhabit the 

 deep sea, and only a very few specimens have been 

 captured in more than a few fathoms of water. 



The Schizopoda, however, present us with many 

 curious abysmal forms. Most of the genera of this 

 order belong to the pelagic plankton, and many of 

 them are known to possess the power of emitting a 

 very strong phosphorescent light. Several genera, 

 however, such as Gnollioplicmsia^ Ghlarasins, Eucopia^ 

 Bentheuphausicij &c., never seem to leave the great 

 depths of the ocean, and nearly all of these genera 



