||Mus"ca (?), n.; pl. Muscæ (#). [L., a fly.] 1. (Zoöl.) A genus of dipterous insects, including the common house fly, and numerous allied species.

&fist; Formerly, a large part of the Diptera were included under the genus Musca.

2. (Astron.) A small constellation situated between the Southern Cross and the Pole.

||Muscæ volitantes (&?;). [L., flying flies.] (Med.)Specks or filaments apparently seen moving or gliding about in the field of vision. Their appearance is often a symptom of disease of the eye, or of disorder of the nervous system.