19,1 Light: Notes on Philippine Termites, II 27 
Clypeal suture.—Divides clypeus transversely into a distal 
anteclypeus and a proximal postclypeus. Lacking in some 
forms. 
Labral suture.—Between anteclypeus and labrum. 
HEAD REGIONS 
The head sclerites are not clearly marked, particularly in 
the soldier, hence the areas or regions referred to are necessarily 
more or less indefinite. 
Labrum (“Oberlippe” of Holmgren).—Upper lip. 
Lingula (Fuller, 1915).—Anterior hyaline extension of labrum 
found in certain soldiers (of Macrotermes, for example). 
Anteclypeus (‘“Clypeoapicale” of Holmgren) .—Distal region 
of clypeus between labial and clypeal sutures. 
Postclypeus (“Clypeobasale” of Holmgren).—Proximal region 
of clypeus, between clypeal and clypeofrontal sutures. 
Frons, front (““Transversalband” of Holmgren) .—The region 
bounded posteriorly by the transverse suture, anteriorly by the 
clypeofrontal suture, and laterally by the antennal carine. Not 
at all or imperfectly defined in most soldiers. 
Frontal area (Fuller, 1915).—Forehead (“Stirn’’), including 
frons and clypeus where transverse suture and clypeofrontal 
suture are both obsolete, as is the case in most soldiers. Region 
between fontanelle and clypeal or labral suture, since fontanelle 
is typically located at junction of frontal and transverse sutures. 
Vertex.—The top of the head corresponding to epicranial 
region of insects whose head sclerites are well defined. 
Occiput (occipital region) .—“An indefinite area forming the 
convex caudal extremity of the head.” (Fuller, 1915.) 
Genx.—Sides or cheeks of head. An indefinite area not deli- 
mitated in termites. : 
Ventral genx.—Ventral surfaces of the head lateral to the 
gula including postgenze which are not delimitated. 
Gula (“menton” of Bugnion, “submentum” of Holmgren) .— 
A distinct median ventral sclerite, articulating anteriorly with 
the labium. 
MISCELLANEOUS HEAD STRUCTURES 
Fontanelle—A foramen in the epicranium, usually in the 
frontal suture at its junction with transverse suture. 
Fontanelle plate—The region of the frontal gland marked 
externally as a thickened or darkened area. 
