1324 REVISION OF THE GENUS HETERONYX, 
Eurychelus was established by M. Blanchard as distinct from 
Heteronyx on account of the unusual length of the second joint of the 
maxillary palpi. I have very ordinary looking species of Heteronyx 
in w'hich this joint is quite as long as it should be in Eurychelus, 
but as the species (E. marmoratus, Blanch.), appears to differ in 
facies from Heteronyx, it would not be wise to reject the name 
without having seen the type. 
Nepytis, Er., resembles Heteronyx in having the claws not 
simple, but differs in having 7-jointed antennae. This latter 
character I cannot regal’d as absolutely conclusive of generic 
distinction, but as it seems to be accompanied by an increased 
length of elytra, the genus may very probably be a good one. 
It will thus be seen that in the group of Australian genera 
which would fall into the Heteronycides of Lacordaire, I regard 
Heteronyx as distinguished by the structure of its claws from all 
except Enrychelus and Nepytis, from the former of which I can 
specify no certain distinction (though it is probable such distinc- 
tions exist), while from the latter it differs in its antennae con- 
sisting of more than seven joints. 
To the genus Heteronyx thus defined a very large number of 
Australian species appertam, and it would doubtless tend to 
simplify the task of their identification and classification if they 
could be divided into groups in any degree natural by any tangible 
structural character. But such subdivision, I am of opinion, is 
impossible, although the structural differences among the species 
are so great as to make the subdivision into purely artificial 
groups exceptionally easy. If the attempt be made to form .sub- 
genera on the relation of the clypeus to the labrum, or on the 
number of joints in the antennae, or on the proportions of the 
hind coxae, or the shape of the femora or tibiae, or on the form of 
the labium, it will be found that the nearest allies of any given 
species in one sub-genus are in an entirely different sub-genus. 
Hence, I think Heteronyx should be treated as an assemblage of 
insects forming altogether a very natural and distinct group, but 
with little fixity of structure in any individual organ. 
