304 Mr. G. J. Arrow on 



Australian Rutelida?. Recently Mr. F. Bates lias called my 

 attention to the fact that this genus is not really distinguish- 

 able from Schizognathus as at present constituted ; but the 

 nearest ally of Castelnau's species cannot be exactly deter- 

 mined from the curious fact that, although it does not appear 

 to be rare, the male is not yet known. In all the species at 

 present referred to Schizognathus, on the contrary, the female 

 appears to be by far the less common. 



The forms collected together under the name of Schizo- 

 gnathus will have to be separated when adequate collections 

 are available for study, for they do not constitute a homo- 

 geneous series ; but, although in the absence of the male 

 sex we are dependent on analogical reasoning, there is 

 cause to believe that Paranonca prasina, Cast,, will eventually 

 be found truly congeneric with Schizognathus prasinus, 

 Boisd., and S. Macleayi, Fisch., the typical species of the 

 genus. 



In consulting Hope's description of his genus Stethaspis I 

 have been surprised to find that there is no correspondence 

 with the Fabrician species named as its type, that species 

 having been described from a specimen now in the British 

 Museum. In order to clear up this fresh complication I have 

 examined the original specimens in the Hope Collection, and 

 found, as I was led to expect, that the true Stethaspis is 

 based, not upon the Kew Zealand Meldontlia suturalis, F., 

 but upon the Australian Xylonychus eucalijpti, Boisd. Hope 

 appears to have had specimens of both before him, but tiie 

 one which he identified as the Fabrician species (and which 

 he correctly recorded as from Australia) belongs to the second 

 species. It is probable that it was to the New Zealand insect 

 he referred as a second species of the same genus ; but, he 

 obviouslv did not make any careful examination of it, having 

 apparently no information as to its habitat. There are con- 

 siderable differences between the two forms, but I cannot 

 agree with Lacordaire in placing them at opposite ends of the 

 family. 



There are thus two names for the Australian genus and 

 none for that from New Zealand, for the name given by 

 Boisduval {Micronyx) had been previously used in the Coleo- 

 ptera. Zoologists may differ as to which of the names now 

 emploj'ed should be retained, for Xylonychus was in use many 

 years before the appearance of Hope's name, although generic 

 characters were not attached to it until twenty years after. 

 My own view is that, since a mistaken identification, such as 

 that of Hope, must always be considered possible when the 

 founder of a genus has not had before him the type of the 



