SUPER-ORDER IV EUORNITHES 277 



genera are found in the Miocene of France. Gypogeranus occurs in the 

 Miocene of Africa, and Palaeohorus, a form allied to Polyborus, comes from the 

 Pliocene of Mexico. Harpagornis, a bird much larger than any existing eagle, 

 has been found in the Pleistocene of New Zealand. 



Order 11. PSITTACI. 



The Psittaci, parrots, have a desmggnathous skull devoid of basipterygoid 

 facettes, with the beak so hinged to the cranium as to permit considerable 

 movement. The quadrate has a peculiar, long neck, and there are processes 

 from the lachrymal, post-frontal, and squamosal, which in a number of species 

 unite to form a suborbital bar, a feature not found in any other birds. The 

 tarsus is short, the outer toe reversed. 



Fossil parrots are rare, but the African genus Psittacus is found in the 

 Lower Miocene of France. 



Order 12. PICARIAB. 



The Picariae comprise such a variety of forms that it has been termed the 

 " avian waste-basket," while the limits of the group and its subdivisions are 

 variously defined by difFerent authors. The well-marked groups embraced 

 under the term Picariae, and often, or usually, given the rank of Orders, are as 

 follows : — Pici, Alcedines, Colii, Trogones, Coraciae, Bucerotes, Macrochires, Capri- 

 mulgi, Cuculi, Musophagi. 



That this is not a natural assemblage may be considered as evident from 

 the fact that no diagnosis based on osteological characters alone can be framed 

 to include all members, though a better agreement is to be found in the 

 pterylosis and muscles. It may be regarded as a convenient grouping of 

 heterogeneous forms, including many that have become specialised in some 

 ways, while at the same time retaining other characters inherited from their 

 ancestors, and distinguished by what they lack rather than what they possess. 



The sternum is variable, but the manubrium is lacking, or small, and the 

 posterior margin most often four-notched. The hypotarsus never contains the 

 number of tendinal perforations found in the Passeres, and there are often 

 peculiarities in the arrangement of the toes ; thus some swifts and goatsuckers 

 have the number of phalanges 2, 3, 3, 3 ; the woodpeckers, cuckoos, and 

 toucans have the fourth toe reversed ; in the colies the first toe may be turned 

 forwards ; and in the trogons the first and second toes are directed backwards. 

 The Pici, characterised by a degenerate palatal structure, and the decurved 

 end of the scapula, are united by Fürbringer to form his Pico-Passeres. 



Through the plaintain-eaters, Musophagi, the Picariae seem to point to a 

 distant connection with Opisthocomus and the fowls, while the Caprimulgi are 

 considered as related to the owls, and through the generalised Asiatic tree- 

 swifts, Macropteryx, from which we pass to the true swifts, Micropodidae, and 

 thence to the humming-birds. 



Unitornis, related to the woodpeckers, and Cryptomis, a relative of the 

 hornbills, occur respectively in the Eocene of Wyoming and France. Cypselus, 

 Limnatornis, a hoopoe, Trogon, and Necrornis, one of the Musophagidae, are from 

 the Miocene of France, the last two hinting at ä former more northerly 

 extension of the African avifauna. 



