The number of its folds varies considerably, from three in Caprimulgus to nearly thirty in crow (Corvus).
There are a raven (Corvus), a coot (Fulica), the well-known Sandwich island goose (Bernicla sandvicensis), now very commonly domesticated in Europe; and some flycatchers and thrushlike birds.
The works of the classical authors before mentioned were printed, and other treatises were published by John de Indagine, Codes, Andreas Corvus, Michael Blondus, Janus Cornaro, Anselm Douxciel, Pompeius Ronnseus, Gratarolus, Lucas Gauricus, Tricassus, Cardanus, Taisnierus, Magnus Hund, Rothman, Johannes Padovanus, and, greatest of all, Giambattista della Porta.
For information on artistic anatomy as applied to physiognomy see th catalogue of sixty-two authors by Ludwig Choulant, Geschichte and Bibliographie der anatomischen Abbildung, &c. (Leipzig, 1852), and the works of the authors enumerated above, especially those of Aristotle, Franz, Porta, Cardan, Corvus and Bulwer.
Rooks (Corvus frugilegus) and the Australian "magpie" or piping crow (Gymnorhina) are to be found in New Zealand, but only locally, especially the former.