1908.] some other Fresh-water Crustacea from Tasmama. 469 
This habit of depositing the eggs, which separates Anaspides from all the 
other groups of the Malacostraca, is probably primitive, and it emphasises 
very strongly the isolation of the Anaspidacea from the other Malacostraca, 
all of which have the most constant and elaborate way of carrying the eggs, 
involving radical modifications of structure, none of which the Anaspidacea 
possess. 
I was unable to observe the hatching out of the eggs, but the whole of the 
evidence I could bring together combines to show that the young hatch out 
with the essential if not identical structure of the adult. 
Systematic Position.—The characteristics of Anaspides may be summarised 
in the form of a table setting forth those characters in which it is peculiar, 
and those in which it agrees with the other divisions of the Malacostraca in 
separate columns :— 
Peracaridan. | Eucaridan. . 
(Mysidacean. ) | (Decapoda.) TEES SEES 
Absence of carapace. Auditory organ on first an- Hight free thoracic segments 
Structure of heart. tenne. with eight ganglia corre- 
Filiform spermatozoa. Modification of endopodites sponding. 
of first two pleopods as Oviposition. 
copulatory organs, and Maxillary gland. 
presence of spermatheca. Structure of alimentary 
Absence of lacinia mobilis canal. 
on mandible. Plate-like structure of the 
double series of gills. 
This table will serve to demonstrate the impossibility of including 
Anaspides in either the Peracarida or Eucarida, and since to include it in 
the old group Schizopoda would further stretch the bounds of that already 
heterogeneous collection, it seems desirable to adopt Calman’s term, Syncarida, 
for a division to include Anaspides and its allies, both living and extinct. 
Those characters which Anaspides does not possess peculiar to itself are 
shared either with the Mysidacea or else with the Decapoda, so that I am 
unable to follow Thomson and Sayce in finding special Euphausiid affinities. 
The resemblance to the Euphausiacea only concerns details in the structure of 
the appendages and cannot compare in importance with such characters as 
the elongated heart and the filiform spermatozoa which are actually diagnostic 
of the Mysidacea. The fact that the Anaspidacea seem to skip over the 
Euphausiacea and to link themselves more directly to the Decapoda would 
suggest that the Euphausiacea do not stand in the direct line of Decapodan 
descent, but have been secondarily derived from a primitive Decapod type by 
the loss of certain important characters, ¢eg., the auditory organs on 
the second antenne. 
