The glands occur in groups, and lead into common ducts which open usually so much reduced that the foremost apparent ventral sclerite of the abdomen represents the third sternite.
Below each eye is a cheek area (gena), often divided into an anterior and a posterior part, while a distinct chin-sclerite (gula) is often developed behind the mouth.
The dorsal area of the prothorax is occupied by a single sclerite, the pronotum (fig.
S8, Sclerite between 7th and 8th G, Anterior, and g, pos S9, 8th Sclerite.
Pmst, The promesosternal sclerite or chitinous plate, unpaired.
The five posterior somites of the metasoma constricted to form a " tail," the post-anal sclerite persisting as a weapon of offence and provided with a pair of poison glands (see figs.
Opisthosoma without trace of appendages; its posterior somites narrowed to opistho form a movable tail for the support of the post - anal sclerite, which has no poison glands.
Post - anal sclerite modified as a long, many-jointed feeler.
Post-anal sclerite short and undivided.
An, Orifice within which the caudal a, Movable (hinged) sclerite (sosegments are withdrawn.