BIRDS. 



349 



only species. The parrots or Psittaci agree with the last-mentioned family 

 in the vertebral centra and movable rostrum, but have the first and fourth 

 toes turned baclcwards, while the beak is hooked. Comirus, PsUtacus, 

 Cacatita, Trichoglossiis are typical genera. 



Fig. 341. Carolina paroquet, Conurus carolinensis, from Tenney, after Wilson. 



Section II. SCHIZOGNATH^. Birds in which there is a schizog- 

 nathous palatal structure (p. 355), and the vomer is narrowed and acute in 

 front. The families to some extent parallel those of the desmognathze in 

 appearance and habits. The CecomorpHjE are swimming-birds, in which 

 the feet are webbed, three toes pointing forwards, and the external nostrils 

 are prolonged backwards as a fissure. The family includes the grebes 

 {Colyjnbus and Podkeps), loons {Ut'inator) , sun-grebes {Helioriiis), auks 

 {Aka), guillemots {U?-ia), gulls {Larus), terns {Sterna), and skuas {Ster- 

 corarius). The Tubinares, including the albatrosses {Dioniedea), petrels 

 {Procellaria) , and fulmars {Fnlmanis), closely resemble the cecomorphK, 

 except in the tubular nostrils. They are oceanic in their habitat. The 

 GralL/E are long-legged wading birds in which the toes (three directed 

 forwards) are not usually webbed. The nostrils are either as in the ceco- 

 morphje, or they are closed behind by a rounded edge. The pratincoles, 

 plovers (Charadriiis), Jaca7ia, snipes {Scolopax}, cranes {Grus), and rails 

 (Ralliis), and their allies, are littoral forms, while the bustards {Otis) have 

 lost their wading habits and are truly terrestrial. The Opisthocomi of 

 South America, like all the remaining schizognathous families have three 

 toes directed forwards. In general appearance the single species recalls 

 the Gallinas, but differs in the absence of the basipterygoids, the union of 



