BY THOMAS G. SLOAXE. 413 



Compai'ing the 9 of this species with that of a North 

 Queensland species which I take to be M. dilaticeps, Chaud., the 

 following differences may be noted : In J/, macleayi the head is 

 broader ; the eyes and the post-ocular prominences are much less 

 prominent, the latter being much less abruptly terminated 

 behind ; the prothorax is narrower towards the base and sinuate 

 before the basal angles ; the elytra are much narrower and less 

 widely rounded at apex (those of M. dilaticeps measure 

 16 X 11-4: mm.), the interstices are more raised — especially the 

 seventh — (in M. dilaticeps the third and fifth are more prominent 

 than the seventh, but none is as sharply defined as in M. vi'icleayi). 

 The four posterior tibi?e are more spinose in M. dilaticeps, and the 

 posterior trochanters are more bluntly rounded at the apex. 

 Both species have the abdomen setigero-punctate behind the 

 posterior coxfe — (this feature is also present in the ^ of M. 

 macleayi, but to a much less marked degree). M. dilaticeps and M. 

 macleayi are very distinct from one another, and both are very 

 different from that remarkable insect, Mecynognathus davieli, 

 Macl., which is the type of the genus. 



The Pterostichus Group. 



The Feronides which I now propose to treat of, under the name 

 of "The Pterostichus Group," may be defined briefly, as including 

 all those presenting a combination of the following characters : — 



Mandibles without a setigerous puncture in the groove (scrobe) 

 on outer side. Elytra bordered on base ; a strong plica on inner 

 surface near edge, the lateral margin usually interrupted on each 

 side of apical curve where the plica joins it.* Mentum with a 

 distinct median tooth or projection. 



According to Dr. Horn another feature of great classificatory 

 importance characterises the group, viz., the contiguit}' of the 

 posterior coxa? j but the genus Huwalosoina is aberrant in this 



* Dr. Horn's words are {I.e. p. 137) "margin strongly interrupted pos- 

 teriorly and with a well marked internal plica," but I think a slight modi- 

 fication is necessary ; for, in the genus Homalo^oma the margin is not 

 interrupted posteriorly," though the plica is as strong as usual 



