the Tenebrionidffi of Australia &c. 97 



chiefly in tlie form of the elytra and in the short metastemum, 

 the latter character being an exceptional one in its subfamily. 

 The female apparently only differs from the male in being 

 broader and more bulky. 



Mychestes lignarius. 



M. fuscus vel fiisco-ferrugiueus, squamulis pallidioribus dispersis, 

 supra fortiter tuberculatus. 



Hah. Queensland (in rotten wood). 



Dark brown or ferruginous brown, covered with loosely set 

 small paler scales, and strongly tuberculate above ; antennary 

 ridge convex anteriorly ; clypeus truncate, its junction with 

 the head forming a broad deep groove ; prothorax broader 

 than the elytra, much rounded and bituberculate at the sides ; 

 the disk with a double row, slightly arched forwards, each of 

 four tubercles ; scutellum rounded, prominent ; elytra ovate, 

 raised at the sides, somewhat flattish above, each with a row 

 of three large tubercles not contiguous to the suture, with a 

 fourth but smaller tubercle in the same line behind, and at 

 the sides seven nearly as large and irregularly arranged in 

 two rows ; legs somewhat hispid, the claws ferruginous ; an- 

 tennaj slightly setulose, the third joint as long as the two next 

 together. Length 4 lines. 



ISOSTIRA. 



(Subfamily Opatrin^.) 



Cli/peus apice integer ; labrum trausversum, baud siuuatum. 

 Paljoi maxillarum secariformes. 

 Prothorax elytris arete aptatus. 

 Epipleurce clytrorum postice defieientes. 



Of this genus I have only a single specimen, and, as the 

 males (and commonly the females) of the Opatrina? have 

 mostly dilated anterior tibite, whilst this has them of the ordi- 

 nary form, it is possibly a female ; or the character may be 

 common to both sexes. The genus, however, allied to Opa- 

 trum, Fab., in the last three characters of the above diagnosis, 

 is essentially differentiated by the clypeus and upper lip. The 

 antenna? are rather short, the last six joints moniliform, form- 

 ing a tolerably distinct club ; of these the seventh to the tenth 

 are very transverse ; the labial palpi arise from the central 

 portion of the labium, and not from its base as in OjKitrmn 

 {0. sabulosum). The prothorax is more convex and overhangs 

 the head, and is closely applied to the elytra. All the tibia? 

 are subfusiform or a little contracted at the extremity. The 

 tarsi are slender and villous beneath. 



