4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134 
arms. Their posterior counterparts, the hypostomal sutures, are absent. 
The EPISTOMAL SUTURE (es) is a very distinct suture connecting the 
two anterior tentorial pits across the face. This suture is the external 
indication of a deep inflection, which results internally in a strong 
epistomal ridge that forms a brace between the anterior mandibular 
articulations. 
The CLYPEOLABRAL SUTURE (cls) separates the anteclypeus and the 
labrum. It is well developed and is regarded by Ferris (1942, 1943) 
as a primary segmental line. 
The CLYPEAL SUTURE (cs) is a very shallow fold on the dorsal sur- 
face of the clypeus. It divides the clypeus into a ventral anteclypeus 
(ac) and a dorsal postclypeus (pc). It is often only faintly indicated. 
Ocuar suTUREs (os) are present and surround the compound eyes 
at their bases. 
An ANTENNAL SUTURE (as) entirely surrounds each antennal socket. 
AREAS OF THE HEAD CAPSULE 
The demarked areas of the cranium are the clypeus, frons, antennal 
and ocular sclerites, parietals, postocciput, genae, subgenae, and post- | 
genae. 
The cLypEus (cl) is a broad sclerite typically supporting the an- 
terior mandibular articulations at its basal angles and the labrum at 
its distal margin. A clypeal suture (cs) transversely divides the 
clypeus into a ventral anteclypeus (ac) and a dorsal postclypeus (pe). 
The clypeus bears numerous long inconspicuous setae which are closely | 
appressed to its surface. 
The Frons (fr) is a large area bounded dorsally, laterally, and _ 
ventrally by the postfrontal, ocular, and epistomal sutures, respec- 
tively. The frons bears the antennal sockets. The facial portion is 
provided with long setae which lie between the antennal sockets and 
in two lines on either side of an imaginary vertical midline. There 
are no ocelli. 
The ANTENNAL SCLERITES (asc) are extremely narrow rings sur- 
rounding the antennal sockets. They are too faintly indicated to be | 
included in a drawing of this scale. . 
The OCULAR SCLERITES (osc) are very faintly indicated narrow | 
eee 
rings, which surround the enormous compound eyes. 
The PARIETALS (par) are a pair of sclerites that encompass most | 
of the dorsal and dorsolateral areas of the cranium, extending laterally | 
to the genae and posterolaterally to the postgenae. The two sclerites 
are separated on the dorsal surface of the cranium by the median | 
coronal suture. | 
