Part 44

Dissepiment: a partition wall: applied to the forming septa separating the coelom-sacs in the embryo; also the thin envelope about the members in obtect pupae.

Dissilient: bursting open elastically.

Distad: toward the distal end.

Distal: that part of a joint farthest from the body.

Distant: remote from: standing considerably apart.

Distichous: applied to antennae when lateral processes originate at the apices of the joints and bend forward at acute angles to them.

Distiproboscis: the outer third of the proboscis in Muscid flies, bearing the labella.

Distychus: bipartite: separated into two parts.

Ditrocha: Hymenoptera; that series having the trochanter two-jointed.

Diurnae: day fliers: applied to butterflies.

Diurnal: such insects as are active or habitually fly by day only.

Divaricable: able to spread apart or divaricate.

Divaricate: straddling or spreading apart: when the wings are lapped at base and diverge behind: tarsal claws when arising at opposite sides of the joint and separating widely.

Divergent: spreading out from a common base; in Coleoptera, tarsal claws are divergent when they spread out only a little; divaricate when they separate widely.

Diverse: unequal: differing in size or shape: of various kinds.

Diverticulum -la: an oft-shoot from a vessel or from the alimentary canal usually blind or sac-like: applied to the caecal tubes or pouches: any extensions or evaginations of the hypodermic.

Dividens (vena): Trichoptera; 1st anal (Comst.).

Dog-ear marks: in bees: small, subtriangular marks of light color, just below the antennae (Cockerell).

Dolabriform: hatchet-shaped: compressed, with a prominent dilated keel and cylindrical base.

Dolioloides: applied to obtect or coarctate pupae.

Dominant: a character more constant and conspicuous than any other: a type or series occurring in large numbers both as to genera, species and individuals and in which differentiation is yet active.

Dorsad: extending or directed toward the upper side.

Dorsal: of or belonging to the upper surface: in Diptera, that face of the laterally extended legs visible from above.

Dorsal bristles: see dorso-central.

Dorsal diaphragm: the wings of the heart, or the very thin membrane upon which these muscles rest: = pericardial diaphragm, q.v.

Dorsal gland orifices: in Diaspinae, oval orifices arranged in more or less distinct rows on the surface of the pygidium, through which is discharged the material of which the dorsal scale is formed.

Dorsal glands: see last preceding title.

Dorsal line: in caterpillars, extends longitudinally on the middle of the back or dorsal.