422 



DR. P. CHALMERS MITCHELL ON THE 



been employed in classification, but to the minute configuration 

 of the bones. 



Sternwn. — In Gadow's valuable synoptic table ( Vbgel, in Bronn's 

 Thier- Reich, p. 79), he states that the external spine is very large 

 in Grues (in which he includes Aranius) and veiy small in Rhino- 

 chetus, and that the internal spine is absent in Grues and in Rhino- 

 chetits. With regard to the internal spine, I confirm his statement 

 for Cranes, Rhinochetus, and both species of Armnus. The 

 external spine is certainly small in Rhinochetus, but it was also 



Text-figure 5. 



Slioulder-girdle articulations in Graiform Birds. I. Balearica. 11. Grus 

 {australasiana & carwncnlata) III. Aranius cftganteus. IV. BJiinocJietus Icagv.. 



A. Acracoracoidal process of coracoid. C. Coraeoid. CI. Clavicle. P. Procora- 

 coidal process of coraooid. S. Scapula. 



small in both species of Armnus. In the examples of Grus 

 that I have examined (G. aitstralasianu and G. carunmdata) the 

 external spine wa,s very large and hollowed for a coil of the 

 windpipe. In an example of Balearica, on the other hand, it was 

 as minute as in Aramihs and RhinocheUts. The sex of the skeleton 

 had not been noted, but it appears probable that the huge 

 external spine of Cranes is developed in connection with the 



