BY THE REV. T, BLACKBURN. 
1325 
As regards the sculpture of the species, the entire absence of 
geminate striation on the elytra, almost universally present in the 
allied genera, is very noticeable, and the decided tendency of the 
prothorax to take the form of being lobed behind is common to 
all, or nearly all, the species that I have seen. 
A few remarks will be necessary on the characters that I rely 
upon for the distinction of species. 
The character best fitted for the formation of primary groups is 
to be found, I think, in the shape of the labrum and clypeus and 
the relation of the one to the other. The upper border of the 
labrum shows, in most species, a tendency to be dilated in an 
upward direction, but in very varying degrees. In some species 
this dilatation is very slight, and the labrum is entirely below the 
level of the upper surface of the clypeus (as in most of the allied 
genei’a), but in others it is so strong that the upper surface of the 
labrum rises to, or above, the level of the upper surface of the 
clypeus, from the front of which it appears to project upwards^ 
in which case the anterior margin of the clypeus is usually 
emarginate for its accommodation, and the reflexed margin of the 
same is interrupted in the middle. I propose then to divide the 
genus into two main groups, the first containing those species 
in which the clypeus is free from the labrum, the other those in 
which the labrum rises to or above the level of the clypeus. 
Nevertheless, a few species in which the relation of the labrum 
and clypeus is exceptional, — being either (a) as in the first group 
Imt with the labrum exposed by profound emargination of the 
clypeus, or (b) with the relation evidently connecting the species 
with the second group, but the labrum not quite sufiiciently 
erected to place it accurately there, — 1 have thought it most 
intelligiVjle to isolate as a group of intermediate forms, by which 
means the two main groups are fairly homogeneous in respect of 
this particular character. 
An inspection of the ventral segments will show that (invari- 
ably, as far as I have .seen) one or two transverse lines of hairs or 
bristles is to be found on each of them, which 1 have called the 
