442 NEW SPECIES OF AUSTRALIAN COLEOPTERA, 



middle; abdomen rather strongly convex along middle of under- 

 siu"face, and legs unarmed, and somewhat thinner. 



Hah. — N. S. Wales : Richmond l^iver(Macleay Museum). 



Belongs to a rather numerous group of species that, at first 

 sight, all look much alike, but are usually readily distinguishable 

 by the antennje, legs, and under-surface of the males. In general 

 appearance, it is very close to R. parvidens, but the front tibiae of 

 the male are more conspicuously armed in the middle, the meta- 

 sternum differently armed, and the antennae not quite the same. 

 R. quadritnberculata, to which it is also allied, has the armature 

 of the front tibiae nearer the apex than base. R. adnmhrata also 

 has the tibial armature nearer the apex than base, and differs also 

 in the metasternum and antennae. R. qtiadriceps has the seventh 

 and eighth joints acutely produced inwards, but is very close in 

 other respects. R. yrandis appears to be allied, but its female 

 (the only sex known) is described as having its apical ventral 

 segment bi-impressed. There are several species, the females of 

 which almost exactly fit the description oi R. grandif<. R. optata, 

 from Victoria, is described as having the prothorax " with no 

 trace of the central fovea." Its legs are not mentioned, but it 

 belongs to a group, the males of which nearly always have very 

 distinctive legs. 



The head is sometimes considerably darker than the prothorax 

 (both sexes), the dark joints of the antennae vary in number from 

 five (6th- 10th) to two (9th-10th). From some directions, the 

 seventh joint appears no wider than the sixth; the ninth, on some 

 of the males, appears to have a small process on one side of its 

 apex, but this may be due to matted pubescence. 



RyBAXIS MICTASTERNALIS, n.sp. 



^. Pale reddish-castaneous, abdomen somewhat darker, legs 

 (knees excepted) and palpi flavous. With short pale pubescence. 



Head with a fairly large, round, closed fovea close to each eye, 

 a shallower one in front. Antennae thin, none of the joints trans- 

 verse, fifth slightly larger than sixth, and just perceptibly larger 

 than fourth, eighth smallest of all: ninth distinctly longer and 

 wider than eighth, and smaller than tenth; eleventh subovate, 



