546 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Trachea {-ae): minute tubes conducting air from the spiracles to all parts of 
the insect body. 
Transverse: having the largest dimension at right angles to the main axis. 
Trophi: the movable parts surrounding the mouth. 
Truncate: cut off squarely at the end. 
Tympanum: the external membrane covering the sensory organ on each side 
of the basal segment of the abdomen of Locusts; sometimes applied also 
to those on the front tibiae of the Tettigoniidae. 
Unicolor: of one color throughout. 
Upper margin of tegmina: sometimes but unwisely applied to the inner or 
posterior margin of the tegmina in Orthoptera which is uppermost or 
dorsal in the resting position. 
Valves (of ovipositor): the four chitinous pieces making up the ovipositor, 
prominent in Tettigoniidae and most Gryllidae, less so in Acrididae, and 
not evident in Mole-crickets. 
Veins: the rod-like stiffenings of the tegmina and wings, chiefly longitudinal 
in direction. 
Velum: = pa\\iuin; the membrane closing dorsally the cavity of the subgenital 
plate. 
Venter: the under surface of the body or of a single segment. 
Vertex: the anterior dorsal part of the head between and in front of the eyes. 
Vestigial: reduced in size; degenerate; existing as remnants of a previously 
functional organ. 
Wing-pads: the undeveloped wings of the nymph or pupa. 
Wings: the organs of flight, including the anterior pair or wing-covers. 
Xerophile; -ous: living in dry places. 
