on two sides and by the dorsopleural suture
and dorsocentral region on the two others.

Dorsolum: the mesoscutum.

Dorsopleural suture: Diptera; the lateral suture between dorsal and
pleurum from the humeri through the base of the wing: separates the
mesonotum from the pleura.

Dorso-ventral: in a line from the upper to the lower surface.

Dorsulum: the mesonotum before the scutellum, with the wing
sockets: also, specifically, the meso-scutellum.

Dorsum: the upper surface: in Coleoptera; often confined to
meso- and meta-thorax: Odonata; includes mesepisterna and meso- and
meta-thoracic terga: Diptera; upper surface of thorax, limited by the
dorsopleural sutures laterally, the scutellum posteriorly and the neck
anteriorly: Lepidoptera; the lower or inner margin of the wing.

Draw-thread: the silk-producing gland.

Drone: in Hymenoptera; the male bee.

Duct: a channel, tube or canal for carrying a secretion from a gland to
the point of discharge.

Ductus ejaculatorius: the single duct or tube formed by the union of
the vasa deferentia from each side, through which the seminal fluid is
ejected into the vagina.

Dufour's gland: that gland, in Hymenoptera, that secretes the alkaline
portion of the poison carried by the sting.

Duodenum: the chylific ventricle; also applied to the first section of
the digestive tract just behind entrance of malpighian tubules.

Dupion: a cocoon spun by two silk-worms together; also the coarse
silk from such a cocoon.

Duplicate -us: double.

Duplicate-pectinate: having the branches of a bipectinated antenna
alternately long and short.

Duple: double, or twice.

Durus: hard.

Dusky: somewhat darkened; pale fuscous.

E

E: as prefix, is privative and means without.

Ears: organs of hearing, as on the first tibiae or on the first abdominal
segment of some Trichoptera.

Ebenine: black like ebony.

Eburneous: ivory white.

Ecalcaratus: without a spur.

Ecaudate: without tails or tail-like processes: usually applied
to wings : = excaudate.

Ecdysis: the process of casting the skin; moulting.

Echinate: set with prickles.

Ecology: the science of the relation of organisms to each other and to
their surroundings: = ethology. {Scanner's comment: Ethology
nowadays refers to studies in animal behaviour,
not directly to ecology.}

Ectad: extending outwardly from within.

Ectal: belonging or relating to the outer surface.

Ectoblast: the outer wall of a c