JouK. Hoy. Soc. WExS'Pekx Aus-tr.'.lta, Vol. XIT, No. 17. 149 
Conti-ilnitions from tlio Dopnvtmout of Biology, University of 
Western Australia — No. 8. 
A Description of Two New Terrestrial Isopodls from Western 
Australia, by Professor Geo. E. Nicholls, D.Sc., b.L.S., and Helena 
M. Barnes, B.Sc. 
{:nc(ul July 13, 192(i. Published August 10, 1920.) 
A few specimens of one of the terrestrial .Isopods which form 
tlie subject of the present contril)utiou were first taken by one 
of us (U.K.N.) in January 1924. These were found hiding mider 
nmss growing upon the shaded side of a giant Karri, Nearly Uvo 
years later (Nov. 192.)), when a, field instruction class Avas held 
at Nornaliip they Avere obtained in larger numbers. The greater 
part Avere taken along the bank of the Frankland Hiver under 
laroe loys in the immediate wake of an extensive and still burning 
l)ush Ore, l)ut they Avere nowhere really ]dentiful. 
The animal is (piite small and its inconspicuous colouring AA-ith 
its habit of curling iij) into a i>all and rolling away when dis- 
turbed renders it by no means an easy object to collect. Tts 
generally s])inous condition also helps greatly to conceal it among 
the del>ris into which it usually falls. 
Such a remarkable develo])inent of spines, it is Avorthy of 
note, a]>pears to be paralleled only in a Natal species, Al'ermania 
sjii)i()S(t (tollinge, Dijdocxochus {Ciihdi'is) echiucitus Riandt, fiom 
Brazil, and Cubans lon<}is}>iuis Ricliardson, recorded from Panama. 
Whether this has I)een imle])endently <levelo])ed in the four species 
and should l)e attributed merely to convergent e\mlution or Avhether 
it is to be considered as indicating community of descent is not 
easy decide. The facts of distri])ution would perhaps favour 
the latter alteniativ*' and in tins vieAV, it is a ([uestion Avhethef 
the South American and Australian forms, at least, should not 
be removed from Cubaris and assigned to a distinct genus. The 
South African species of Diploexochuu described by Panning (1924), 
do not shoAV similar develo])ment of spines. Akermania appears 
