338 MISCELLANEA ENTOMOLOaiCA, 



and about a yeai' ago I described in the " Insects of Gayndah " 

 five others, angusticornis, elnngakdus, Kingii, Mastersii, and 

 Westwoodii. 



In the present Paper I add largely to the number of species, 

 but I regret to say that I cannot contribute much to our know- 

 ledge of the habits and history of these very curious insects. 

 Two observations only can I add to the scanty information we at 

 present possess, one is, that some of the species are nocturnal, as 

 I have frequently known them to fly into lighted rooms ; the 

 other, that one species at least A. brevis Westw. is gregarious. 

 On one occasion I found upwards of fifty of them clustered 

 together under a small piece of the loose bark of a gum tree, and 

 Mr. Masters informs me that he has met with as many as twenty 

 or thirty in a similar situation. This by no means proves how- 

 ever that it is a bark insect, as in both the instances alluded to, 

 the ground was very wet, and the insects may have taken to the 

 tree for protection and shelter. I have repeatedly during floods 

 in the Murrumbidgee taken large numbers of species of Gatad- 

 romus, Aptinus, Steropus, Poecilus, and other undoubted ground 

 beetles under the bark of trees. 



In order to simplify to some extent what in such a homo- 

 geneous group must always be diSicult — the detection of the 

 species — the following synopsis will be useful : 



Arthkopterus. 

 Section 1. — Antennse with the joints 2 to 9 three times or 

 more broader than the length. 



1st. Thorax longer than bi'oad, body naked. 



A. Mastersii, MacLeay, W. 

 • — . cylindricollis, n. sp. 

 — . Waterhousei, n. sp. 



A. Macleayi, Don, 



— . elongatulus, MacLeay, W. 

 — . bisirmatus, n. sp. 



— . angidicornis, n. sp. 



2nd. Thorax longer than broad, body hairy. 



A. Hopei, Westw. 



— . 'Riverince, n. sp. 



— . nigricornis, n. sp. 



-. — . picipes, n. sp. 



A. montanus, n. sp. 

 — . subampUatus, n. sp. 

 — . humeralis, n. sp. 

 — . ovicolUs, n. sp. 



