24 
The Queensland Naturalist. 
July, 1925 
(a) The liviiio- Phreodrilidae are the descendents 
of ati old cold cdimate ancestral stock which once 
inhabited the Southern lands, and are now I'e* 
stricted to ar(*as Avhere these conditions are nov" 
attained; or 
(b) The Phreodrilidae are the I’emnants of a 
stock whieli has ])een unable to meet the de- 
mands for existence under normal and tem- 
jjerate conditions, and consequent!}' have taken 
up an abode, or liave ))ersisted in places where 
the strn^o-le for existence i,s far less keen. 
Before discussing' these conclusions, we will mention 
several facts which will tend to makf‘ the issue more 
easily understood. 
Firstly, the Phreodrilidae uiuhnibtedly show marked 
affinities, when phylot^enetieally considered, with the 
Lumbriculidae, and the latt(u* are as tridy restricted to 
the Xorthern. as the former to tlie Southern Hemisphere. 
Secondly it would a])pear that the Phreodrilidae are 
not capable of mi^n*atino> across sea barriers, as are so 
many of the Oligochaeta. They do uot meet with the same 
chances of migration at the iiands of man like many 
terrestrial Oligochaeta — a fact which is ex])lained by their 
habitat, and that the chief medium servingfor conveyance 
in the hand.s of man is eithtu* soil or water from re- 
stricted localities, and which is supported by the absence 
of Phreodrilidae except in the restricted habitats men- 
tioned ahovt‘. and by the fact that as yet no species is 
knoAvn as being common to any two of the land 
areas where the family is i*epresented. Tn this con- 
nection we eannot hut point out that in no division of 
the Tnvertehrata are the species more valid since they 
are framed Avithont exception uot only on exeeedingiy 
M^ell-marked external differences in connection with 
setae, etc., but also on peculiarly accentuated internal 
differences. There is no room for synonymy in any of 
the grou]n 
The restriction of the family to the Southern Hemi- 
sphere certainly finds its ])arallel in the case of many 
oth(‘r grou])s. bnt it Avould seem that in the case of the 
Phreodrilidae no explanation other than that of the 
existence at one time of a direct connection between the 
continents of the Southern Hemisphere is satisfactory. 
The Liimhriculidae Avhich occupy a corresponding phylo- 
