1866.] PROF. W. LILLJEBORG ON THE CLASS OF BIRDS. 11 



They generally walk and run with ease or very fast, and mostly 

 live in damp places, near swamps or on the banks of watercourses. 

 The majority fly fast and with ease ; some fly badly. They live 

 generally in the middle ("mittlere," Faber) monogamy*. Prsecoces. 

 A great number of the Ardeida are Altrices. 



Order 6. Brevipennes, Dumeril. 



The wings more or less rudimentary, and not adapted to flight. 

 Pectoral bone without crista. A small number of large birds that 

 run fast, and may be considered typical of the whole group. Their 

 structure exhibits a strong tendency towards the mammalian. Some 

 are said to live in the middle monogamy, others in single monogamy, 

 and others again in polygamy. Praecoces. 



Order 7. Galling, Linne, 



The legs of a mediocre height, and the entire crus feathered f. 

 The wings adapted to flying, but generally rather short and obtuse, 

 and more or less bent. They run fast ; but are easily fatigued by 

 flying, and then hide among rocks, bushes, grass, &c. Some live in 

 polygamy, but the majority live in middle monogamy. Prsecoces. 



Third Division or Subclass. 

 INSESSORES, Vigors ; Bonaparte. 



The entire crus and the lower part of femur free. The coat of 

 feathers generally extends at least to the tarsal joint J. The hind 

 toe with its base on a level with that of the anterior toes§, and 

 very seldom missing. 



Order 8. Pullastr.e, Sundevall. 



The bill not covered by a cere at the base, but generally naked there, 

 and with an inflated skin at the nostrils. The point of the upper 

 jaw rounded, but very seldom bent down in the form of a hook. 

 Three toes directed forward, and not united together. The large 

 upper wing-coverts of the first row on the lower arm extend beyond 

 the middle of the cubital quills. Two carotides communes. The 

 majority fiv very fast ; some do not fly so well, but these run fast. 

 The majority live in double monogamy, a few in middle or single 

 monogamy {Penelope), and a few in polygamy (Crax). The majo- 

 rity are Altrices, the others Praecoces. 



Note. — This order is evidently an intermediate group between 

 Cursores and Insessores. The Talegallince, Peaelopidce, and Di- 

 dunculidce exhibit some tendency towards the Accipitres. 



* Both the old ones attend to their young, but do not carry food to them, 

 letting them, under their care, hunt for their own food. 



t The genus Orfyxelos, Vieill., is an exception to this. 



\ Didunculus (Pleiodus) deviates from this, and has the lower part of the crus 

 naked. 



§ The Cathartini form an exception to this. 



