Mr. R. Shelford's Studies of the Bkdtidac. 273 



help in determining this species and for sketches (repro- 

 duced here) of Erichson's types. The species may be 

 re-described as follows : — 



Piceous, nitid, impunctate, rather depressed. Antennae rufous, 

 except a few basal joints which are piceous. Tegminal rudiments 

 absent. Supra-anal lamina, {^) sub-quadrate, exceeded by the cerci 

 and sub-genital lamina, posterior margin scarcely emarginate, angles 

 not rounded, fimbriate, margins not serrate, ( 5 ) trigonal, rather 

 shorter than cerci, apex very slightly emarginate, margins serrate. 

 Sub-genital lamina ( ^ ) scabrous, quadrate. Coxae unicolorous, legs 

 piceous. 



Length (type c? ) 12 mm., (type $) 16 mm.; pronotum 4 mm. 

 X 6 mm. 



Tasmania (Berlin Mus., types; Oxford Mus.; Vienna 

 Mus.); New South Wales, Sydney {W. W. Froggatt); 

 Victoria (Melbourne Mus.) ; South Australia, Northern 

 territory (Adelaide Mus.). 



6. P.ferox, sp. n. (PI. VII, figs, la, 7h.) 



^ . Piceous, nitid, impunctate, laterally finely scabrous. Lateral 

 margins of thoracic tergites slightly incrassated. Tegminal rudi- 

 ments absent. Angles of abdominal tergites 5-9 produced as acute 

 spines, lateral margins of tergites 6 and 7 strongly denticulate. 

 Supra-anal lamina sharply triangular, apex terminating in two 

 spines, margins serrate. Cerci short, acuminate. 6th and 7th 

 sternites with a complete row of spines on their posterior margins, 

 these spines on the 4th and 5th sternites confined to the lateral 

 parts of the posterior margins. All the sternites finely tuberculate 

 laterally. Sub-genital lamina quadrate, scabrous, genital styles 

 stout, spiniform, exceeding the cerci in length. Legs unicolorous, 

 piceous. 



Total length 33 mm.; pronotum 8 mm. x 12 mm. 



Central Australia {Spencer- Gillen Expedition), (Mel- 

 bourne Mus., type ; Oxford Mus.). 



7. P. armata, Tepp. (PI. VII, figs. 8, 9.) 



Platyzosteria armata, Tepper, Tr. R. Soc. S. Australia, 

 xvii, p. 84 (1893). 



Dark castaneous, nitid, minutely punctate, laterally finely scabrous. 

 Antennae rufous, except for castaneous basal joint. Pronotum with 

 impressions and inconspicuous rugosites. No tegminal rudiments. 



TRANS. ENT. soc. LOND. 1909. — PART II. (MAY) T 



