flight; one pair, the
primaries, attached to the meso-thorax; the other, the secondaries,
attached to the meta-thorax.

Wing covers: those parts of the chitinous cuticle of larvae, nymphs or
pupae which cover the rudiments of the wings of the imago: the
forewings of an imago when they are thicker than the hind wings and
cover them when at rest: see elytra; tegmina.

Wings of the heart: the series of diagonal and other muscular fibres
above the diaphragm in the pericardial cavity: see pericardial
diaphragm.

Wing cells: areas inclosed by veins: reference should be had to the
figures illustrating venation and to the special terms applied to the
cells.

Winglets: small, concavo-convex scales, generally fringed at tip, under
the base of the elytra in Dytiscidae.

Wing-pads: undeveloped wings of pupa or nymph.

Wing-scale: in Hymenoptera, = tegula; q.v.

Workers: the undeveloped females in the social Hymenoptera; also
those sexually undeveloped Termites that are not soldiers.

X

Xanthophyll: the yellow of autumn leaves; one of the substances
found in the blood of insects.

Xenobiosis: see symbiosis.

Xerophilous: applied to species living in dry places.

Xylophaga: wood-eaters: applied in several orders.

Xylophagous: feeding in or upon woody tissue.

Xyphus: a spinous or triangular process of the meso-sternum in many
Hemiptera, and some other insects.

Y

Yellow: used without modification is sulphur or lemon yellow.

Yolk: the nutritive matter of an egg as distinguished from the living,
formative material; = deutoplasm.

Z

Zona: a belt or zone; as of distribution.

Zonite: = arthromere or somite; q.v.

Zooenite or Zooenule: = zonite.

Zygoptera: those Odonata, having the fore and hind wings subequal in
width, venation comprising a quadrilateral, not a triangle; nymphs
with caudal tracheal gills.

ADDENDA.

Calacobiosis: see symbiosis.

Cleptobiosis: see symbiosis.

Dulosis: see symbiosis.

Coxal file: in some aquatic Coleoptera a series of striations just above
the hind coxa of male and, perhaps, a stridulating organ.

Coxal plates: plate-like expansions or dilations of the coxa: specifically
in aquatic Coleoptera on the posterior pair.

Ecto-parasite: one that is attached to the external surface of the host.

Ento-parasite: one that feeds within the body of the host.

Embioptera: an ordinal term proposed for the Neuropterous family
Embidae.

Hamab