230 REVISION OF THE THYNXID.E OF AUSTRALIA, I., 



b. Prothorax not emarginate. 

 a'~. Two apical segments red. • i?. ijinguiculus, n.sp. 



B. Prothorax not produced at the anterior angles. 

 a. Prothorax truncate anteriorly. 

 a"2. Black, prothorax and mesopleurse red. R. pvothoraciciis, n.&p, 



6'2. Black, abdomen except basal segment ferruginous. 



R. hrermsciihis, n.sp. 



$ $ . i. With a depression on each side of the prothorax near the 

 posterior margin. 



A. Median segment without a carina. 



a. Median segment trapezoidal, much broadened to the apex. 

 a^. Black; the mesothorax, median segment, legs and pygi- 



dium ferruginous. R. piigionafus Sauss. 



b'^. Wholly castaneous. R. acuhaius Sauss. 



b. Median segment subcylindrical, very little broadened to the 



apex. 

 a2. Black, the legs and margins of the abdominal segments 



testaceous-brown. R. tiimidus, n.sp. 



B. Median segment carinated. 



a. The carina very slightly developed. 



a"2. The depression on the prothorax slight and only on the 



posterior margin. R. dmticniatus, n.sp. 



b'^. The depressions large, almost reaching anterior margin. 



R. prothoracicus, n.sp. 



b. Carina very prominent. 



a'~. Prothorax rounded anteriorly. R. brevinsculus, n.sp. 



b". Prothorax with the anterior angles prominent and toothed 



R. alexins, n.sp. 

 ii. Without depressions on the prothorax. 



A. Head narrow, much longer than wide. 



a. Wholly castaneous. R. bkhn-s Sauss. 



B. Head subquadrate, slightly longer than wide. 

 ft. Shining, abdomen finely punctured. 



a2. Light ferruginous ; head, mesothorax and disc of ab- 

 dominal segments black. R. consangiiinens, n.sp. 



b. Opaque, abdomen longitudinally rugulose. 



a^. Antennae, legs and two apical abdominal segments ferru- 

 ginous. R. comparafus Sm. 



c. The truncation of the median segment concave. 



ft2. Wholly castaneous, R. ca-^tanetis Sm. 



R. ALEXIUS, n.sp. 

 ^. Clypeus densely clothed with white pubescence; head punc- 

 tured, a carina between the antenna? broadly rounded at the 



