Part 158

Vasiform orifice: in Aleurodidae, an ovate, triangular or semicircular opening on the dorsum of the last abdominal segment.

Veinlets: in Orthoptera, are the minute transverse ribs or ridges between the longitudinal veins.

Veins: the chitinous, rod-like structures supporting the wings, and especially those extending longitudinally from base to the outer margin nerves nervures; nervules.

Velum: a membranous appendage of the spurs at the apex of anterior tibia in bees a broad process at inner end of fore tibia.

Velum penis: the thin membranous covering of the male intromittent organ also applied to ether covering or shield-like structures of the penis.

Velutinous: velvety: clothed with dense, soft, short hair, like velvet.

Vena: a vein.

Vena dividens: that longitudinal vein of secondaries that marks the beginning of the anal area: = anal 1 (Comst.).

Vena plicata: on the wings of Dermaptera, the vein around which the folding occurs.

Vena spuria: = spurious vein: q.v.

Venation: the system of chitinous frame-work supporting the wings: in Lepidoptera, the veins are usually referred to by numbers which are as follows: on primaries: 1 = anal; 2 = cubitus 2; 3 = cubitus 1: 4 = media 3; 5 = media 2; 6 = media 1; 7 = radius 5; 8 = radius 4; 9 = radius 3; 10 = radius 2; 11 = radius 1; 12 = subcosta: on secondaries: 1, 1a, 1b = anal; 2 = Cubitus; 3 = cubitus 1; 4 = media 3: 5 = media 2; 6 = media 1; 7 = radius 1; 8 = sub-costa. See plate III for typical venations of all orders.

Venter: the belly: under surface of abdomen as a whole and of each ring.

Ventose: inflated; puffed out.

Ventrad: extending or directed toward the under side.

Ventral: pertaining to the under surface of abdomen: in Diptera, that face of the leg which is inferior when laterally extended.

Ventral chain: refers to the series of ganglia of the nervous system.

Ventral comb: in Trichoptera, a transverse row of fine teeth on venter.

Ventral diaphragm: is a fine membrane covering the central nerve cords and ganglia: also called ventral heart.

Ventral heart: = ventral diaphragm, q.v.

Ventral plate: a thickening of the blastoderm of an egg from which the embryo, but not the amnion or serosa is formed.

Ventral scale: in Diaspinae, the under part of the puparium, interposed between the insect and the plant.

Ventral tube: in Collembola, a tube or tubercle proceeding from the ventral side of the first abdominal segment.

Ventricose: with a big belly: distended; inflated.

Ventriculus: the true stomach, = chylific ventricle; q.v.

Ventri-meson: the middle line of the ventral surface of the body.

Ventro-cephalad: toward the lower side and anteriorly.

Ventro-dorsad: extending from belly to back.

Venules: the branches of the main veins.