174 



Annals ok the Carnegie Museum. 



other forms the basitemporal area is much contracted, while in the 

 dried skull the tympanic cavity is so exposed that no little care is re- 

 quisite to locate its exact boundaries. The foramina for the pneumo- 

 gastric, glossopharyngeal, hypoglossal nerves and internal carotid ar- 

 tery, relatively occupy their usual sites, as seen elsewhere in the Class. 



Upon this inferior view of the skull we really see the under side of 

 the occipital condyle, as its form and articular surface appear only in 

 full view when the skull is looked at directly from behind. 



This direct posterior view of a bird's skull is a very instructive one, 

 a fact that was thoroughly appreciated by so talented an anatomist as 

 Garrod, who presented us with a number of them among his valued 

 papers, as for instance where he makes the telling comparisons among 

 the skulls of Chaitiia derbiaiia, ClocpJuii^a i/iage/Ia/i/ccx and Mitiia tu- 

 bcrosa (P. Z. S., 1876, pp. 189-200). 



Fig. 7. The sternum ai Ardca lierodias, viewed from helow. Natural size. 



Such a view of the skull of this Heron is shown in Figure 5, where 

 the broad crotaphyte fosste are seen, separated from each other in the 

 median line above by an exceedingly narrow space. The supra-occi- 

 pital region stands out prominently, partially overhanging the sub- 

 circular foramen magnum. Regularly reniform, with the notch up- 

 wards, the large occipital condyle is here better seen, jutting directly 

 backwards from its lower margin. Beneath, and in the middle region, 

 the pterygoids and the four carinations of the palatines come into view. 

 These are flanked on either side by the ponderous quadrates, which 

 latter show the large jjneumatic foramen in each, leading into their 

 hollow interiors. 



