from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The middle of the three divisions of the thorax of an insect, bearing the middle pair of legs and the first pair of wings.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The middle of the three segments of the thorax of an insect
from the GNU version of the Collaborative International Dictionary of English
- n. The middle segment of the thorax in insects. See Illust. of coleoptera.
from The Century Dictionary and Cyclopedia
- n. In entomology, the second or middle one of the three divisions of the thorax, situated between the prothorax and the metathorax, and bearing the second pair of legs and the first pair of wings. When very large, as in dipterous insects, it is simply called the thorax.
Vertebrates, the skeleton of the prothorax to the bones of the cerebellum, of the palate, and the pieces of the larynx, the skeleton of the mesothorax to the parietals, interparietals, and opercular bones, and that of the metathorax to the skeleton of the thorax of Vertebrates.
Many of the names which he proposed are still in use; it was he who introduced the terms prothorax, mesothorax, and metathorax, for the three segments of the insect's thorax.
He used Geoffroy's _Loi de balancement_ to explain cases of correlative development, such as the relation between the size of the front wings and the development of the mesothorax.
Hypopleura: in Diptera, the space over the middle and hind coxa, between the metapleura and pteropleura: the side of the metasternum: the mesepimeron of the mesothorax.
Humerus: the shoulder: in Coleopteran; the basal exterior angle of elytra: in Diptera, the anterior superior angles of the mesothorax: in
Metathorax: the third thoracic ring or segment; bears the hind legs and second pair of wings; variably distinct; sometimes closely united with the mesothorax and sometimes appearing as a portion of the abdomen.
Humeral callus: in Diptera, is a rounded callus forming the anterior superior angle of the mesothorax.
Mesosternal lobes: in Orthoptera; = mesosternellum, q.v. Mesosternellum: in Orthoptera, two median lobes of the mesosternum, one on each side of the deep median notch: in general, the sternellum of the mesothorax.
Mesepisterna: in Odonata, - the oblique lateral pieces of mesothorax, meeting dorsally in a ridge.
Bright green; the vertex, two oblique stripes on the prothorax, meeting in the centre of its anterior margin, a broad longitudinal stripe on the disk of the mesothorax, and the sides of the scutellum and postscutellum deep purple.