rhamphotheca Ornith.
(ræmfəʊˈθiːkə)
[mod.L. (J. C. W. Illiger Prodromus Systematis Mammalium et Avium (1811) 150), f. Gr. ῥάµϕος beak + θήκη sheath.]
The modified integument, usu. horny but in some birds leathery, that covers the jaws and forms the bill.
| 1870 Baird & Cooper Ornithol. I. 567 Ramphotheca [indexed as rhamphotheca], the horny covering, or sheath of the jaws. 1890 [see gnathotheca s.v. gnatho-]. 1972 P. Stettenheim in D. S. Farner et al. Avian Biol. II. i. 45 In ptarmigans (Lagopus spp.) and certain other grouse (Tetrao spp.), the rhamphotheca is shed intact after the breeding season. |