1894.] The Classification of Arthropoda. 221 
I, Leptostraca. 
Order I, Nebaliade. 
I, Eumalacostraca. 
Order I, Stomatopoda. 
Order II, Thoracostraca. 
Order III, Arthrostraca. 
On the whole, I accept the conclusions of Grobben as to the 
relationships of the various groups, and have, like many other 
zoologists, regarded the Phyllopods as the ancestral stock. I 
think that this is shown by, among other points, the structure 
of the appendages, regarding which I fully accept the conclu- 
sions of Lankester? (81). I do not regard the nauplius stage 
as indicative of a naupliform ancestor, but as an introduced 
feature, for which view the arguments adduced by Claus and 
Dohrn, seem valid. The ancestor of the Phyllopods must have 
been an elongate poly-somitic animal with lamellate append- 
ages, the basal portions of one or more “legs” serving at the 
same time as both locomotor and manducatory organs. In 
short, my views as to the ancestral form are much like those 
adopted by Bernard (’92), although I cannot accept all of his 
conclusions as to the steps of the evolution. 
Crass J[I—AcERATA. 
Branchiate Arthropods, in which the branchial folds, de- 
veloped from the abdominal appendages function as gills, as: 
lungs, or as trachee. The body is divided into cephalothorax 
and abdomen, the line passing behind the sixth pair of ap- 
pendages. The genital ducts open upon the first abdominal 
somite. The anterior postoral ganglia unite to form a gan-- 
glionic ring aronnd the esophagus; the median eyes are in-- 
1I regard ig s (’87) Syncarida as a group of Amphipoda s scarcely more’ 
than family 
ues mat not accept Lankester’s views, and claims that sbieyldes shows 
that Lankester’s sixth endite is the endopodite and the flabellum the exopodite, in 
Support of which he cites the observations of Claus (’73, p. 20). I cannot find there 
or anywhere else in Claus’ paper any evidence which is not capable of being inter- 
Preted in full harmony with Lankester’s view that the 5th and 6th endites of the Phyl- 
lopod limb are endopodite and exopodite respectively, while the flabellum is the ho- 
Mologue of the epipodite cf the “typical” Crustacean limb. 
15 
