376 PROFESSOR E. RAY LANKESTER. 
“ velated to”? the Arachnida, but definitely to be classed in 
that group). The points in which they agree are probably 
points in which they both approach the common ancestor of 
the Arachnida and Crustacea—but each of them presents 
clearly and definitely the dominant and distinctive stryctural 
attributes of its own class or branch of the pedigree of 
those Appendiculata which have appendages modified to serve 
as jaws—namely, the Arthropods or, better, Gnathopods. 
