THE PHYLOGENY OF THE HIGHER CRUSTACEA, Io] 
The general conclusions of this highly suggestive and in- 
teresting paper may be summarised as follows :— 
The Malacostraca are descended from the phyllopods, among 
which Nebalia is their nearest relative. The Euphausiacea are 
the most primitive Malacostraca. The decapods originated from 
the Euphausiacea, although the most primitive decapods, the 
Natantia, are now widely separated from this ancestral form. 
The Squillacea stand by themselves, their nearest, although dis- 
tant, allies being the Euphausiacea. They show in certain 
points a more primitive condition than any other Malacostraca ; 
although, as a whole, they are highly modified. The Mysidacea 
are also derived from the Euphausiacea ; although they are so 
different from them that they must be placed in a distinct order, 
and the group Schizopoda must be abandoned. The Mysidacea 
have no close relationship to the decapods. The Cumacea arise 
from the Mysidacea, and the amphipods and isopods from a form 
between the Mysidacea and the Cumacea. The amphipods and 
isopods are not a primitive group distantly related to the Po- 
dophthalmata, but they are the most highly specialized of the 
Malacostraca. 
He gives the following as his phylogenetic classification of 
the Crustacea :— 
Amphipoda, 
Isopoda, 
Cumacea, 
Mysidacea, 
Lophogastrida, 
Squillacea, 
Decapoda, 
ae 
Eupha'usiacea. 
Nebalia 
ve 
Phyllopoda, 
