630 Mr. D. Sharp and Mr. F. Muir on the Comparative 
highly peculiar Passalidae with the other divisions of 
Scarabaeidae. 
In the Passalidae the median lobe is large and globular, 
membranous around the median orifice, which is large ; 
small median struts are sometimes attached to its base. 
The lateral lobes are consolidated, have not the character 
of lobes, but form a plate. The basal-piece is distinct, 
except in Aulacocyclus (fig. 18), where it is lost or entirely 
consolidated to the lateral lobes. The internal sac is 
large. All these characters are approached in T7'rox 
omacanthus, but in neither Lucanidae nor in Scarabaeidae 
do we find any suggestion of a direct connection with 
Passalidae. 
SINODENDRIDAE LU CANIDAE 
LAMPRIMIDAE 
SCARABAEIDAE 
PASSALIDAE 
TROGIDAE 
AFFINITIES OF THE SCARABAEIOID FAMILIES 
The great importance of the Trogidae in this division 
is evident, but becomes singularly significant when we 
realise that it also approximates greatly to the Byrrhoidea 
series. 
In concluding our scattered remarks as to the Scara- 
baeoidea we may say that we think that the taxonomy of 
this division is still very imperfect. We greatly regret 
that we have not been able to examine some of its most 
enigmatic forms (e.g. Nicagus),* but we feel that it would 
* Thanks to Mr. E. A. Schwarz, F. Muir has since been able to 
examine the long disputed Nicagus. It has a well defined median 
lobe, with median orifice on dorsal aspect of tip ; well defined lateral 
lobes a little longer than the median lobe, broad at the base and 
gradually tapering to a pointed tip, the bases meeting on the ventral 
