ACRIDID^. 633 



** Keel of the protborax very slight. 



I Hind tihise not blackish. - . _ . Ceramicum. 



f I Hind tibiae blackish. _ . - . tenebiifeium. 



b. Hind border of the protborax angular. - - - contractura. 



A. transiens and A. tenebrosum are the most typical of the preceding 

 species. A. contractum is slightly aberrant. 



ACRIDIUM TENEBRIFERUM. 



Foem. Piceum, subtus fulvum ; caput et prolhorax Inteo inlerruple 

 biviltata ; caput breve, fas tigio subhexagnnali, fronte scabra luteo 

 varia ; prolhorax scaber, vix carinatus, margine poslico valde rotun- 

 da to ; prosterni spina conica, breviuscula, subacuta ; pedes fulvi, 

 tibiis tarsisque qualuor anterioribus piceis, femoribus posticis nigra 

 binotalis, tibiis tarsisque posticis nigricantibns ; ala anticce corpore 

 multo breviores. 



Female. Piceous, moderately stout, tawny beneath. Head and pro- 

 tborax with an interrupted luteous stripe on each side. Head short; tip 

 of the vertex flat, subhexagonal ; front scabrous, partly luteous; keels 

 strongly marked ; inner keels nearly parallel; outer keels diverging slightly 

 towards the face. Eyes much rounded on the hind side. Protborax 

 scabrous, with a very slight keel ; transverse impressed lines strongly 

 marked; fore border nearly straight ; sides slightly rounded ; hind border 

 much rounded. Prosternal spine conical, slightly acute, rather short. 

 Legs tawny ; four anterior tibiae and tarsi piceous; hind femora with two 

 black marks on the outer side; hind tibia and hind tarsi blackish, the 

 former a little shorter than the hind femora. Fore wings much shorter 

 than the body. Hind wings cinereous, pellucid; veins black. Length of 

 the body 13 lines; expansion of the fore wings 21 lines. 



a. Celebes. From Madame Ida Pfeiffer's collection. 



Australia. 



A. Size very large. _ - - _ - mactilosum. 



B. Size moderate or small. 



a. Tip of the vertex depressed. 

 * Antennas not flattened. 



f Prolhorax tuberculate. - - - _ tuberculatum. 

 ff Protborax not tuberculate. 



X Prosternal spine slightly forked. - - - furciferum. 

 JJ Prosternal spine not forked. 



§ Prosternal spine long, conical at the tip. - - angustifrons. 



§§ Prosternal spine very obtuse. - - - - pyrrhocnemis. 



§§§ Prosternal spine hardly long, semicircular at the tip. obtusum. 



§§§f Prosternal spine acute. - . - - virescens. 



** AntenncB flattened. 



f Tip of the vertex hexagonal. - - - - exclusum. 



f f Tip of the vertex subheptagonal. - - - alienum. 



b. Tip of the vertex not depressed, ... pilipes. 



A. angustifrons, A. obtusum, and especially A. pilipes and A. exclusum, 

 are aberrant species of the genus. 



