sb. and a. Zool. [f. Gr. σφήν wedge (cf. SPHENO-) + ETHMOID.] One of the cranial bones in batrachians, situated at the base of the skull; the girdle bone. Also sphenethmoid bone.
1875. Huxley, in Encycl. Brit., I. 754/1. As it takes the place of the ethmoid, presphenoid, and orbito-sphenoids, it may be termed the sphen-ethmoid.
1877. Huxley & Martin, Elem. Biol., 218. Appearing at the base of the skull, at the front end of the parasphenoid, is the girdle-bone or sphenethmoid.
1903. Encycl. Brit., XXXV. 896. Sphen-ethmoid bone.
