CHAPTER XVII 



OF THE DEEP-SEA CRUSTACEA OF THE INDIAN OCEAN 



Our general knowledge of the deep-sea Crustacea, like 

 that of the deep-sea fishes, is one of the results of 

 the expeditions and surveys specified in a former 

 chapter, among which that of H.M.S. Challenger 

 stands out in historic relief. Here we must restrict 

 ourselves to a glance at a few of the species discovered 

 by the Investigator, and as our view is intended for 

 the amateur rather than for the specialist, it may, 

 perhaps, be as well to preface it with a brief state- 

 ment of the present classification of the whole group. 



The class Crustacea, as now existing, is divided 

 into two great sub-classes, the Entomostraca and the 

 Malacostraca, with a small connecting-link between 

 the two, represented by Nebalia [Leptostraca). 



The Entoinostraca include a host of marine and 

 freshwater forms, mostly of small size, in which the 

 segmentation of the body, when not obscured or 

 actually obliterated by parasitism, is indefinite and 

 inconstant. In this sub-class are comprised (i) the 

 multisegmented Phyllopoda, with Branchipus as a 



