BY W. MACLEAY, ESQ., F.L.S. 369 



form a distinct subgenus. It differs from the most common 

 group of the larger Australian Feronice, named by Chaudoir 

 Notonomus, in having the third joint of the antennae much longer 

 than the fourth, from Uhytistermis of the same author in the 

 thicker and more truncate palpi, while from Homalosoma, TricJi- 

 osternus, Prionophorus, Loxodactylus, and Ghlcenioidius of Chaudoir, 

 it is still wider apart. 



The sculpture of the elytra is unlike that of any of the 

 family I have seen, more resembling, in fact, that of a true 

 Carahus than of a Feronia. 



Each elytron has two broad, deep grooves, extending from the 

 base to the apex, and in the bottom of each groove there is a 

 fine rounded " carina." Near each lateral margin there is a row 

 of large more or less distant punctures. The extreme apex is 

 rounded, but the sides a little above the apex are profoundly 

 sinuate. 



My only specimen of this insect is a female. It was found, I 

 believe, in the upper valley of the Richmond River. 



When on an Entomological excursion to the Murrumbidgee 

 in the spring of last year, Mr. Masters and I captured, in con- 

 siderable numbers, in the neighbourhood of Mundarlo and Tar- 

 cuttah, a species of Tmesiphorus, which we invariably found in the 

 society of a small red ant. So invariable was the association that 

 whenever on turning over a log we found some of the ants we 

 knew that a search in their passages would certainly lead to the 

 discovery of some of these attendant beetles. 



The ant answers very nearly to the genus Ectatomma of 

 F. Smith. It is undescribed, I give it therefore a name and 

 description. 



Ectatomma socialis. 

 Long. 2| lin. 



Piceo-rufa subtilissime dense punctulata parce aureo-pubescens, 

 capite quadrato subconvexo subtus hirto, oculis parvis 

 lateralibus ante medium positis, abdominis petiola brevi 

 lata postice truncata, segmentis terminalibus subhirtis, 

 pedibus longis flavis. 



