Abstract
Those species described in the present issue are characterized by quadrantic labial palpi, strongly elongated apiculus of antennae with more than 15 segments on nudum, well marked lower median vein which reaches near base of vein 4 in the discoidal cell of the forewing, and vein 5 being vestigial and inconspicuous on hindwing. With a few exceptions there is a remarkable similarity in the male genitalia of these species: dorsum with a large dorsal membranous area at the middle; scaphium with a pair of unci having the distal portion liable to be bilobed, and with a pair of lateral processes produced from the connecting portion with tegumen; gnathos with a distinct cochlear; valvae with saccus small, ill-developed, posterior portion of harpe expanding dorsally and divided into two lamellate or angled processes with minute serrations; phallus generally stout, somewhat dilated distally, apex oblique, vesica opened posterodorsally without sharply defined cornutus, suprazonal sheath of aedeagus with dorsal membranous area longitudinally ; juxta broad, lamellate. The authors consider that these species may be akin to each other primarily on account of the common characters of their genitalia, but more materials are needed to define the relationship between those and the other species of the "Plastingia group" as EVANS put it.
