(from the article `passeriform`) The lower leg of passerines, the tarsometatarsus (usually called simply the tarsus), is normally covered by a horny sheath (podotheca). Exceptions ... Found on http://www.britannica.com/eb/a-z/p/83
Pod`o·the'ca noun ; plural Podothecæ . [ New Latin , from Greek poy`s , podo`s , foot + ... case.] (Zoology) The scaly covering of the foot of a bird or reptile. Found on http://www.encyclo.co.uk/webster/P/114