CATALOGUE 



FOSSIL BIRDS. 



Class AVES. 



Order I. CARINAT.E. 



The sternum is provided with a carina, except iu some cases 

 where the power of flight has been lost. The coracoid and scapula 

 do not anchylose completely, and their long axes form an acute, or 

 at most a slightly obtuse, angle ' ; the former bone being of an elon- 

 gated type -. The fureula, as a rule, is well developed. The ischium 

 generally extends upwards towards the ilium ^ ; and the ilia are 

 divergent, with a short preacctabular portion. The lateral arches 

 of the cervical vertebraj may send down processes to meet in the 

 middle line below the centrum. The vomer is generally narrow 

 behind \ and does not interpose between the pterygoids, palatines, 

 and basisphenoidal rostrum. The quadrate is not overlapped by the 

 squamosal, and its proximal articular head is divided into two facets . 

 As a general rule, there is a bridge over the groove for the extensor 

 tendons of the foot on the anterior surface of the distal extremitj^ 

 of the tibio-tarsus ; the fibula is more or less closely attached to 

 that bone ; and the talon (hypotarsus) of the tarso-metatarsus is 

 complex iu existing forms. 



' In Ocydronms and Did us. 



- Hesperornis is exceptional in this and the preceding point. 



^ Separate in the Odontornithes. 



■* Not 30 in the Tiii-amidte, where the strueture is Ratite. 



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