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species there are also numerous small granules or large punc- 
tures, either without order or in sinuous or straight rows, in- 
terspersed among the systematic series, but in no case known 
to me capable, on careful inspection, of confusion with the 
latter. In a single species ( T. Brucki, Har.) some of the 
systematic series are wanting, in a few species the systematic 
series are all similar inter se, in most of the species they 
(especially their tubercles) are alternately larger and smaller. 
Among these, the second, fourth, etc., series are the larger 
in some species, the third, fifth, etc., in other species. In 
these elytral characters I have found no tendency to varia- 
tion. An invariable specific character is to be found also 
in the degree of declivity of the antero-lateral part of the 
elytra connected with the comparative prominence and 
shape of the humeral callus and the development of the front 
part of the sublateral systematic series; but these characters 
are difficult to express in words, though easy to appreciate 
when specimens are examined. To this exten$, however, the 
character just mentioned can be used with advantage; if a 
Trox be looked down upon from exactly above it (so that the 
two lateral margins appear symmetrical) in some species 
(the less convex ones) the whole of the actual margin is 
visible on both sides as an even line, but in others its front 
part, from the point of view indicated, appears on both sides 
interrupted by its own deflexion or by the protrusion (be- 
yond its outline) of the outline of the humeral callus or of 
the tubercles of the sublateral or lateral systematic series. 
I should add that I have not found very sat/sfactory char- 
acters in the prothorax. The sinuosity of the margins of 
that segment is extremely variable within the limits of a 
Species, as also the sharpness of the sculpture of the prono- 
tum. Undoubtedly there are species in which the normal 
condition of the lateral margins is strongly and others in 
which it is feebly (or not) trisinuate, species in which nor- 
mally the hind angles are weli developed, and others in 
which they are normally more obtuse; but I have not suc- 
ceeded in discerning any really workable distinction in these 
characters in more than two or three species. The greater 
or less declivity hindward of the part of the pronotum in 
front of the basal lobe seems to be a character calling for 
attention in identifying species. 
Attention must be called to the fact that it is impossible 
to form a correct idea of the sculpture of a Trox without the 
removal of the indumentum, with which almost all speci- 
mens are coated. This generally requires the use of a strong 
brush (such as a tooth-brush), which, fortunately, the hard 
texture of the body renders practicable without injury to 
the specimen. 
