^go CORACIIFORMES chap. 



ross-pink breast, black markings on the sides of the head, 

 and black tips to the remiges and rectrices. Mclittophagus gularis 

 of West Africa is glossy black above, with bright blue on the fore- 

 head, rump, wings and median tail-feathers ; the throat is crimson, 

 the lower surface black with blue streaks ; the wing- quills are 

 for the most part rufous margined with black. 



The Old World Families Bucerotidae and Upupidae are united 

 under the latter appellation by Dr. G-adow,-' who recognises the 

 Sub-families Bjtcerotinae or Hornbills, Upupinae or Hoopoes, and 

 Irrisorinae or Wood-Hoopoes; but the two aforesaid groups should 

 decidedly be kept separate. 



Fam. V. Bucerotidae. — The Hornbills derive their name from 

 the immensely developed bill and casque, or helmet, found in such 

 forms as Biiceros (p. 395), though the excrescence in Aceros and 

 some species of ZopJwceros is rudimentary. It may be mentioned 

 that the huge beak of the Toucans denotes no affinity to this 

 group. The casque — open in front in Bucorvus — is more or less 

 filled with cellular bony tissue, or with an almost solid mass of bony 

 columns in Bhinoplax ; the mandibles are occasionally serrated. 

 The metatarsi are short, save in the terrestrial Bucorvus, and 

 are rough and scaly ; the toes have broad flat soles, the second and 

 third being united for one phalanx, the third and fourth still further. 

 The powerful wings have eleven primaries, and from ten to sixteen 

 secondaries, while the under coverts do not perfectly cover the base 

 of the quills. The tail has ten rectrices and is usually long, though 

 shorter in Bucorvus ; it is either square or graduated, and has the 

 two median feathers much elongated in Rhmoplax and Ortholo- 

 phus. The furcula is U-shaped, the tongue rudimentary; the after- 

 shaft is wanting ; there is no down on the adults or callow young ; 

 and the eyelashes are prominent, a rare feature among birds. In 

 most forms the atlas (p. 5) fuses with the axis. 



These arboreal birds, termed "Calaos" in French, frequent deep 

 tall jungle or cultivated districts near rivers, up to five thousand 

 feet ; most, if not all, of the species descending from the trees in 

 the morning and evening, when they have been observed bathing 

 in streams, and digging up loose soil with their beaks. Bucorvus 

 spends much of the day upon the ground searching for food. The 

 flight, often prolonged to considerable distances, is heavy and slow, 



^ Bronn's TMer-Meich, Aves, Sysl. Theil, pp. 233-235. The Hoopoes used once 

 be considered Passerine. 



