COLEOPTERA. 
45 
Longit. (rostr. incl.) 9—11 lin. = 20—25 millim. 
Latit. hum. 2i— 2f lin. = 5— 6 T | millim. 
Long, antenn. (in $ 22 millim. long.) 27 millim. 
Patria : Brasilia. Dom. Serville. 
This species is the most widely and deeply depressed in the elytra of 
of any of the insects in this genus. It is, in proportion to its length, the 
broadest of the depressed species. The rostrum is the most robust amongst 
them, and the shortest, in proportion to its development in the male as well 
as in the female. The thorax is the broadest and shortest, proportionally 
more so than in Pt. nebulosus , and it is impressed like the latter and Pt. elon- 
gatus. The elytra are broader in proportion to their length than in all the 
depressed species, except perhaps in large males of Pt. nebulosus , and 
hardly more elongate than in Pt. viridanus: they are much more deeply 
depressed on the disc than in the largest males of Pt. elongatus , in which 
the depression is at its greatest extent, more roundly and obliquely flattened 
to the ante-apical callosity, which is slightly conical, short, and does not 
attain to the perpendicular level of the apex, which is subobliquely cut off 
behind it: their sides, from the widening of the depression, are subperpen- 
dicularly inflected and subcompressed to the margin, which is more roundly 
dilated beneath the base than in Pt. elongatus. The marginal stria is also 
more clearly indicated,—as much so, at least, as in Pt. tricostifrons (which 
has the margin as roundly dilated beneath the base, but the sides are ob¬ 
liquely inflected). The borders of the discoidal depression are more ele¬ 
vated than in any other species, subcarinate, and placed between the fourth 
and fifth striae. The alternate interstices, the innermost posteriorly, the 
median (which forms the cariniform limit of the depression) and the exter¬ 
nal one almost entirely are a little elevated, narrowly convex, and poste¬ 
riorly marked with short fuscous hairs, more evident in the male, —a 
character which I have found in this species only. 
The general colour is that of Pt. elongatus , but the whitish common 
band of the elytra is much wider, agreeing with the breadth of the de¬ 
pression ; its sides are much less sinuate, or rather they are very slightly 
emarginate in the middle and above the apex; the median emargination 
is very shallow, extending only between the fourth and third striae, having 
a depth of hardly more than one interstice, and the posterior is obsoletely 
indicated, so that the ordinary large maculae formed by them are reduced 
to intra-lateral lineolae. 
