CRUSTACEA OF THE DEEP SEA 137 



accompanied only by the most trivial differences 

 in structure. To take one example, the " Pink 

 Shrimp" {Pandalus montagtii), which we may find 

 commonly between tide-marks on our own coasts, 

 differs only in inconspicuous details from species of 

 the same genus living at a depth of 600 fathoms ; 

 while other genera of the family Pandalidae range 

 downwards to 2,000 fathoms or more, without any 

 important divergences in structure. 



I 



