alternative definition added over 15 years ago by Andy Deans
The part of the subgenal margin of the cranium posterior to the mandible, usually narrow, but sometimes extended mesally as a hypostomal plate or as a hypostomal bridge in the ventral wall of the head.
Reference: Snodgrass, R. E. 1935. Principles of insect morphology. McGraw-Hill Book Co., Inc., New York & London 667 pp.
Cross reference:
None provided.