306 REVISION OV AUSTRALIAN T.EPIDOf TKRA, vi., 



other examples of Metrocampa, 10 arises clearly out of 9 (Text- 

 fig 3), and anastomoses with 11. The structure in Text-fig. 2, in 

 Metrocampa, has resulted from the non-development of the short 

 basal portion of vein 10. The occasional non-development of 

 portions of veins ma\' give rise to very puzzling appearances in 

 the genera Boannia and Hhinodia. In Rhinodia. 11 usually 

 anastomoses with 12, but the non-development of the Vjasal por- 

 tion of 11 causes that vein to arise apparently out of 12. In 

 Boannia^ it will be shown, 11 may appear to arise from 12 in 

 quite a difl^erent way, the basal stalk of 10 and 11 having become 

 separated from the distal part of 11, which remains connected 

 with 12 by what was, originally, a connecting bar. 



I think it is impossible to ariange the genera in any tabular 

 scheme, and even an artificial key would be most difficult to 

 construct, and of doubtful value. But it is possible to give a 

 general idea of the relationship of the genera. Firstly, there is 

 a primitive and distinctly Australian group, of stout hairy build, 

 the terminal joints of the palpi rather long, the thorax often 

 crested, and veins 10 and 11 arising separately from cell. This 

 may be called the Chlenias-gvou^. From it arose the Thalahia- 

 group, in which 10 arises from 9: and the ^we/o?*«-group, more 

 slenderly built, with short palpi, less hairy, 10 and 11 long- 

 stalked, and sometimes with a fovea. In all the genera of these 

 groups, the neuration shows little variability. Secondly, a not 

 very dissimilar form like Cleora^ with similar neuration, but 

 shorter palpi than Cklenias, and with a large fovea, gave rise to 

 a large group of genera, in a few of which {Lyelliana, Metrocampa) 

 10 arises from 9, but in most 10 and 11 are long-slalked or 

 coincident. This is the ^oarwia-group. The Abraxas-gvou'p, 

 so different in colouration, appears to be closely correlated in 

 structure. But there appear to have been also developed aiore 

 smooth-scaled forms with a strong tendency for 1 to arise out 

 of 9, or to become coincident with it. This is the Deiliuia-group, 

 represented in Australia by Casbia and its allies. 



I have made no attempt to record unrecognised species 

 Species which T have been unable to examine are marked thus f. 

 Types, unless otherwise specified, are in my collection. 



