392 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
the tcgula at the base of the anterior wing; these dorso-lateral 
lobe-Hke pieces will be referred to in the description as the lobes 
of collar. The anterior region extends laterally over the posterior 
portion of the lateral faces of the propleura down to the bases of 
the anterior coxae. These broad antero-lateral portions of the 
pronotum will be spoken of as the lateral faces of the pronotum. 
The propleura are latero-ventral plates situated in the cervical 
region. The lateral portion on each side gradually narrows 
toward the head; ventrally they meet in a median longitudinal 
line. In the descriptions the lateral and ventral portions will be 
known, respectively, as the lateral face, and the ventral face of the 
propleura. 
The prosternum is a rectangular plate lying on the ventral 
surface and extending from slightly beneath the propleura ante- 
riorly, to between the anterior coxae behind; it is folded upon 
itself posteriorly, causing it to appear narrower behind and, as a 
consequence, triangular in outline. 
The pronotal lobe is the small and comparatively inconspicuous 
elongate region which lies immediately behind the lobe of the 
collar and below the anterior portion of the tegula. 
Mesothorax. — The prescutum is the anterior medial, pear- 
shaped portion of the dorsal surface of the mesothorax. It 
extends forward between the lobes of the collar and posteriorly, 
wedge-like, into the mesoscutum to slightly beyond the posterior 
tangent of the tegulae. A median longitudinal suture divides it 
into similar halves. 
The mesoscutum is the most extensive portion of the dorsal 
surface of the mesothorax. It extends forward on each side 
between the tegulae and the prescutum to slightly under the 
lobes of the collar, and to the bases of the hind wings posteriorly, 
falling short of the latter, however, medially to make room for the 
forward extension of a well-defined quadrate plate, — the meso- 
scutellum. On each side, postero-laterally , the mesoscutum drops 
down abruptly into a deep trough or sinus, — the mesothoracic 
sinus, — which extends obliquely from the scutellum to the base 
of the anterior wing. 
The mesoscutellum, just mentioned, is a quadrate plate sit- 
uated postero-medially with respect to the mesoscutum; it is 
continued on each side as a very narrow transverse piece from its 
