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‘very indistinet toward the apex. The part between these lines is coarsely pune- 
tured, the punctures being regular on each side of the three external lines and 
on the exterior of the subsutural ones. The triangular scutellum, between the 
bases of the elytra, is smooth at its apex. There is a triangular rugose or coarsely 
irrorated area at its base. 
The under surface of the thorax is of a chestnut brown; it is highly polished 
on the areas against which the legs move and strongly punctured on other exposed 
parts, the punctures having a sparse pile of light-brown bristles. 
Legs.—The femora are uniform in size and smooth, each with 1 row of setose 
punctures nearer the posterior ventral margin. The tibie are nearly similar 
in shape and size, bearing externally 3 rather prominent teeth. The fore tibi, 
in addition, have an internal and external apical one. The mid and hind tibie 
have each 1 internal and 2 external apical teeth, armed with a row of smaller 
secondary ones, and all are coarsely punctured. All the tarsi are of about the 
same shape and size, except that the last joints of the anterior ones are slightly 
longer than the others, and the first of the mid and hind tarsi are subconical 
and slightly larger than the succeeding ones. All tarsal joints are setose or 
spinose at their apices. 
Abdomen.—The dorsal abdominal segments are hidden by the elytra; the 6 
visible ventral ones are smooth, except for very sparse punctures and a subapical 
row of setose punctures on each. There is a tuft of brown hairs at the anal slit. 
The hinder exposed part of the abdomen is rounded, smooth, shiny, and sparsely 
punctured. The elytra do not cover the last 2 dorsal segments. 
The principal differences between the female and the male are that the former 
is much smaller and its horn may be a mere tubercle, or, at best, not more than 
one-fourth as long as that of the male. The depression on the pronotum extends 
back less than halfway; the posterior lateral rugose areas are somewhat broader. 
(Pl. 1, figs. 5, 6). The last ventral abdominal segment of the female differs 
from that of the male, in that in the former it is rounded and covered with bristly 
hairs, while in the latter it is markedly emarginate. The ventrum of the abdo- 
men of the female is rather densely covered in transverse rows with bristles, 
except along the apical margins of the segments. The posterior part of the 
pygidium is also densely hairy. Both sexes have on all the thoracic joints, as well 
as at the articulation of the head with the thorax, a fringe of bristles closely 
applied to the surface upon which the part is attached to prevent the entrance of 
foreign matter between the sutures. 
Method of operation of the adult——Vhe method of attack of the adult 
insect was formerly believed to consist in its gnawing into the plant for 
the purpose of feeding upon the soft tissues inside, its eggs not being laid 
in the tree. This view is partly incorrect. Observation has shown that 
the males make burrows, as well as the females, and it is probable that 
they always accompany the latter at the time of egg-laying, retreating 
from the burrow they have made to allow the female access. Dissection 
demonstrates that the stomach of the insect contains no masticated fiber ; 
on the contrary, it is filled with a dark, amber-colored liquid; nor are 
there any fiber cells found in the excreta. The proventriculus or gizzard 
of the insect is not provided with walls for grinding and the mandibles 
are constructed somewhat like the parts of a cane mill through which the 
sugar cane passes in expressing the juice, except that their surface is cor- 
rugated, the elevations of the one fitting into the depressions of the other. 
