THE ARTHROPOD A OF THE DEEP SEA 137 



three or four times the length of the body, is by 

 no means rarely met with in depths of over 400 

 fathoms. 



The genus Glyi^hus captured by the ' Talisman ' is 

 remarkable for the development of a peculiar pouch- 

 like arrangement on the abdomen for the protection of 

 the larvEe during the younger stages of their existence. 



The proof of the existence of a peculiar cray-fish, 

 TJianmastoclieles zaletcca, at a depth of 450 fathoms, 

 was one of the most important contributions to 

 carcinology made by the ^ Challenger ' Expedition. 

 The chelae of this remarkable form are of great but 

 unequal length and armed with long tooth-like spines 

 giving it an appearance not unlike that of the jaws 

 of some carnivorous fish. The shell is soft and the 

 abdomen broad and flattened. There are no eyes 

 nor even eye-stalks, but ' in front of the carapace,' as 

 Sir Wyville Thomson remarks, ' between the anterior 

 and upper edge and the insertions of the antennae, 

 in the position of the eyes in such forms as Asfacus 

 fluviatilis^ there are two round vacant spaces, which 

 look as if the eye-stalks and eyes had been carefully 

 extirpated and the space they occupied closed with 

 a chitinous membrane.' The deep-sea prawn, Psali- 

 dopus^ recently taken in 500 fathoms of water by the 



