Hinds believe that the paired piercers are the inner lobes of the maxillae, and the unpaired piercer the left mandible, the right mandible being absent.
2, IV) in which the slender piercers (mandibles and first maxillae) work to and fro.
First maxillae also modified as piercers; maxillae of both pairs with distinct palps.
Mandibles and first maxillae modified as piercers; second maxillae fused to form a jointed, grooved rostrum.
Within the groove of the rostrum two pairs of slender piercers - often barbed at the tip - work to and fro.
The piercing portions of the latter - representing their inner lobes or laciniaelie median to the mandibular piercers in the natural position of the organs.
The drill brace appears to have been used by Assyrians in the 7th century B.C. Piercers of bronze tapering (58), to enlarge holes in leather, &c., were common in all ages.