PHLM@OBORUS. 149 
subfamily on account of the coarse granulation of the eyes, a feature, however, which 
is not more marked than is to be expected from the large stature of the species. As 
Kichhoff has pointed out, there is no sufficient reason for separating them from the 
Hylesinides. 
These genera are both Neotropical, but Phleotrupes has not yet been found in 
Central America. It is distinguished by the rounded, compressed, and obtuse antennal 
club, the deep excavation of the inner face of the tibie, and the elongate apical joint 
of the maxillary palpus, which is equal in length to both the basal joints. 
In Phieoborus the club is acuminate and scarcely compressed, the tibie are less 
excavate internally, and the apical joint of the maxillary palpi is shorter than either of 
the basal joints. 
A feature noticeable in certain specimens of Phlewoborus is the existence on the 
propleura, above and before the anterior coxe, of a deep circular fovea, lined with 
hairs, and containing, at least in some dried examples, a fatty secretion (Tab. VI. 
fig. 136). It appears to be the structure indicated by Chapuis under the name 
“‘ depressio sternalis,” and is not mentioned by Erichson or Lacordaire. The question 
naturally arises whether it be a sexual character or not, and it is one which has not 
been easy to decide in practice; for although dissection affords a means of correctly 
determining the sex of each of two forms which are known to be male and female of 
the same species, it can furnish only presumptive evidence of the specific identity of 
two forms of opposite sex, and that merely if a large number of each form is examined 
and the sexual organs are found to be constantly male or female. At the time that 
Chapuis’s series of Phiwoborus was before me there was no evidence in favour of this 
character being sexual; all specimens of P. rudis examined, some twenty in number, 
possessed the foveee, no typical examples of P. sericeus did so, But in Mr. Fry’s 
collection, as related further under P. scaber, are specimens which differ only in the 
presence or absence of this organ; and on revising the accessible material, I have been 
led to infer that it is really a sexual feature, characterizing the female, at least in the 
latter species. Whether it is ever present in the male, or absent in both sexes, remains 
to be proved; reasoning by analogy alone, both these things may occur. 
The limits of the species are difficult to ascertain, as the ruge or tubercles which 
make up the thoracic and elytral sculpture are extremely variable in degree of 
development; their number and situation on the elytra, and their differences in kind 
rather than in degree of development, appear to be more reliable characters. 
It may be added that the forms furnished with propleural foveee possess a wider and 
more convex front, and their rostrum is less or not impressed over the mouth ; this is 
in agreement with the presumption that they are females. 
The range of the genus extends from Mexico to Brazil; it has not been found 
in the Antilles. I have seen six forms from Central America which I regard at preseut 
as distinct species; but two may prove eventually to be sexes of the same species. 
