Nichou.s — Two New Fhreatoicids. 
207 
upon the Australian luaiulatul all live, a])])areiitlyj ('veoping beneath 
moss ill highly sheltered situations. In ojteii waters, with more 
active life and ])robably a more al>undant food sup])ly, adaptation 
might bring about the larger body, the expanded joints as aids to 
swimming, larger swimming and respiratory ])leopods, the consequent 
increased importance of the pleon and a greater fecundity. In this 
view the short, almost clubbed first antennae of the larval stage of 
Amj)hisopus would ajtpear merely as recaintulatory, the scaly clothing 
as a flattening and shortening of the fine furdike covering of setae 
of the highland forms. The setae of the basal joints of the pleopods 
could be transmuted to couiiling hooks, as those upon the maxilliped 
(in Eojdireofoicus) a])]H‘ar to liave l)eeii. 
Many of the more iini)ortnnt differences to l)c observed between 
Eoplireafoiens and the sub-aljtine sjuades of Phreaioicufi ap]>ear, how- 
ever, to be more reasonably inteiq>retable as due to loss and retro- 
gression in the latter genus, fto far as it is possible to judge, the 
very ancient V. wiaiKunaiiciisis would seem to find its nearest living 
counterpart in Eoj}]rrcafoicus. 
In the consideration of this (piestion the structure of the South 
African species (which must have been isolated from its Australian 
congeners for an imnumse j)eriod of time) has a distinct ini])ortance. 
r. capeiisis Barnard is <les<-ribed as having the posterior vertical 
groove upon the head, the first antenna very short, and its flagellum 
with but five joints, coxae of ])eraeopoda (juite distinct, fourth 
peraeopod of male sul)-chelate, the basal joint of the first peraeopod 
is figured as setose l)ut witliout coupling hooks, the second pleo])od 
with ])enial filannmt curved only at the a]>ex, short and with terminal 
setae, the telson with prominent terminal i)rojection — i.e., it has the 
general facies of the Kasterii Australian forms. The inner lobe of 
the first maxilla, too, has four plumose setae anil two others retaining 
cilia only at their a])ices. 
In the retention of a secondary cutting edge to tlie right man- 
dible it differs fi’oin these sjiecies and resembles Amphisopus. 
Eophrealoieu.^ and Phrc<(toiropsis. Tlie ])leon, too, is longer rela- 
tively than it is in P. aitsiraHs, but not longer than in one or tAVO 
of the Tasmanian forms and near to that of A mphisopm. In tlie 
extremely elongated condition of the first free peraeon segment it is 
nearest to one or Iavo of the subterranean s]>ecies. 
It is possessed, however, of two features in Avhich it is apparently 
unique, in this family :--(!) the retention of a A'estige of the 
innermost lobe on the second maxilla, Avhich is jdainly figured by 
Barnard, but not referred to in the text, in AA'hich condition it most 
nearly approaches that of the Syncarida; and (2), the existence of 
plumose setae upon the endopodites of the pleopods— no other 
