94 RECORDS OF THE AUSTRALIAN MUSEUM. 



favouring the condensation of the telopodit and the growth of 

 its processes. Wliilst around such regions, taken as centres, 

 in surrounding mountain ranges or in isolated lands and 

 islands, the condition of life are different, enough to slacken or 

 alter the action of evolution. Yet it is to be expected that, 

 under the latter conditions, forms will crop out more perfect 

 under some other point of view still to be ascertained. Such 

 is the case for Leptodesmids in South America, and will likely 

 prove to be the case for Strongylosomids in the Australian 

 continent and surroundings. 



The following is an analytical key to the six known species 

 of Australiosonia : — 



1 (2) — Body with a transverse yellow stripe on the posterior 



half of metazonite ^4. tnuDirer.'^e-fK'niatxDi, ^j. K. 



2 (1) — Body without transverse yellow stripes 3 



3 (6) — Bodv of an uniform colour, or, should the dorsal part 



appear lighter, no definite longitudinal bands are 

 seen . ..4 



4 (5) — Distal part of seminal branch of goiiopods gradually 



thinning out into a spine-like ajtex ; posterior branch 

 two thirds the length of the seminal branch ; end of 



anterior branch not expanded 



.1. hifith-ittii)}!, Silvestri. 



5 (4) — Distal end of seminal branch divided into three tines ; 



posterior branch nearly as long as the seminal bi-anch ; 



end of the anterior bi'ancli spade shaped 



.1. frttij<fitttl , sp. nov. 



<i (3) — Body with one or two deiiiicil liirlit-colonred dorsal 

 bands .7 



7 (8) — Anterior mai'giii of coxal aperture of gon()j)t)ds with 



a large, horizontal lap produced backwards ; posterior 

 margin without process ; posterior (outer) branch of 



gonopods blade-like, cui'ved outside the oi'gaii 



A. liiitii-iiifili-iiriiijuiii, sp. nov. 



8 (7) — Anterior margin of coxal a])ertui'e of gonopods with- 



out a lap ; posterior margin with a stroiiLT tooth-like 

 process dii'ected do\vii\var<ls ...9 



