388 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY 
which it is fused, and the tentorial fossae; laterally, it extends 
somewhat beyond the inner margins of the eyes; anteriorly or 
below it extends more or less over upon the labrum. The lower 
margin is always emarginate. This emargination, however, is 
usually rather variable, and seems to be of no specific taxo- 
nomic significance. It varies not only in depth and width, but 
sometimes also in outline; thus while the outline is as a rule 
rounded, it is sometimes practically obtuse, that is, the edges of the 
emarginated area are straight or nearly so and the lateral oblique 
up-and-down edges form obtuse angles with the horizontal 
transverse edge. This plate varies also in the degree of its 
extension over the labrum. Normally, only the lobes (i. e., the 
apparent extension on each side formed by the emargination) 
extend over the labrum and only slightly, but quite often the 
disc (i. e., the mesal portion) also extends over it and the lobes 
more than normally. Some of the older authors used the term 
"produced" to indicate the latter condition. It is always 
sparsely covered with long, whitish, and sub-erect hairs which 
have their origin in minute punctures. Owing to the fineness 
and sparsity of the punctures the clypeus appears smooth; oc- 
casionally, however, it is more or less markedly roughened. 
The hyperclypeus is the median portion of the front below the 
antennae; its general outline may be said to be that of an isosceles 
triangle. Anteriorly or below it is always broadly fused with the 
clypeus, and its lateral boundaries are somewhat sinuous sutures 
which run obliquely from the tentorial fossae to between and 
alongside the inner margins of the antennal sockets. Except 
rarely, however [usually in grandis (Norton) ], the lateral oblique 
sutures are obsolete, and the region forms an uninterrupted por- 
tion of the front below the antennae. 
The frons or front is the portion of the head lying between the 
compound eyes and is considered as extending from the clypeus 
below to the posterior tangent of the two posterior ocelh above. 
For convenience, the portion of the front lying above the bases 
of the antennae is termed front above antennae; that below, the 
jront below antennae. 
The vertex is the portion of the top of the head behind the 
front; laterally it extends as far as the cheeks. 
The median region of the head above the antennae is raised 
