Order V. ANISODACTYLI. 



Scarcely any two modern ornithologists are agreed as to the 

 affinities between the Eollers and several other groups of Picarian 

 birds, especially the Kingfishers, Bee-eaters, Hornbills, Hoopoes, 

 Swifts, and Nightjars *. All these, except the Hoopoes, have a 

 peculiar and variable arrangement of the deep plantar tendons 

 (see Garrod, P. Z. S. 1875, p. 344). The two tendons coalesce 

 more or less completely either before their subdivision to supply 

 the different digits or below the point at which a slip leaves the 

 flexor perforaiis diyitorum to supply the hallux. 



In other respects, such as the characters of the palate and 

 sternum, the form of the dorsal feather-tracts, presence or absence 

 of caeca, and the nature of the oil-gland, whether nude or tufted, 

 there is much variation, and the majority of the families mentioned 

 differ from each other quite as much as the Passeres and Eury- 

 laemi do. It appears very doubtful whether the Swifts have any 

 affinity to the other groups, and the Caprimulgidce and Podargidct 

 are also isolated. In adopting Gadow's arrangement and leaving 

 the Coraciadce or Rollers, Meropidce or Bee-eaters, Alcedinidce or 

 Kingfishers, Bucerotidce or Hornbills, and Upupidm or Hoopoes in 

 one order, I am very largely influenced by a desire to avoid 

 increasing the number of ordinal groups. 



The Anisodactyli have a desmognathous palate ; basipterygoid 

 processes are rudimentary or absent. Sternal characters vary. 

 There is no ambiens muscle. A hallux is always present, and there 

 are almost constantly three anterior toes, more or less joined 

 together at the base. All the species lay white eggs in a hole, 

 either in a tree or in the ground, and the young are hatched 

 naked. The sexes are alike as a rule, but when they differ in 

 plumage the young resemble adults of the same sex. 



There are five Indian suborders, thus distinguished : 



a. Oil-gland nude ; cca present ; 4 notches behind 



sternum. 

 a'. Two carotids ; manubrium sterni simple, no 



foramen behind it CORACI^E. 



&'. Left carotid only; manubrium sterni complex 

 and having behind it a perforation to receive 

 ends of coracoids MEROPES. 



* Compare Garrod, P. Z. S. 1874, p. 117 ; Sclater, Ibis, 1880, p. 401 ; Forbes, 

 Ibis, 1881, p. 31 ; Seebohm, Classification of Birds and Supplement; Fiirbringer, 

 Untersuchungen, p. 1567; Sharpe, Eeview of Recent Attempts to Classify 

 Birds, pp. 79-81 ; Gadow, P. Z. S. 1892, p. 251. See also yols. xvi and xvii 

 of the British Museum Catalogue of Birds. 



