DEVELOPMENT OF THE SKFLL IN TIIE OSTEICH TEIBE. 181 



Fig. 9. Section of upper ethmoid, showing its alae, in the Rhea. 



Fig. 10. Horizontal section through pars plana of Bhea; 4 diameters. 



Fig. 11. Front view of pars plana and middle turbinal of Bhea, showing a section of the 



lower turbinal ; 4 diameters. 

 Fig. 12. Part of fig. 13; 8 diameters. 

 Fig. 13. Section of combined upper and perpendicular ethmoids of Bhea, showing their 



junction and the coalescence of the right and left lamellae of the perpendicular 



part; 4 diameters. 

 Fig. 14. Ditto, section through the widest part of the inferior turbinals of Bhea; 



4 diameters. 

 Fig. 15. Transversely vertical section through the septum nasi and lower turbinal of 



Bhea further forwards ; 4 diameters. 

 Fig. 16. Similar section through the alse nasi of the same, showing the fibrous pads 



attached to the nasal turbinals ; 4 diameters. 

 Fig. 17. View from within of pars plana of the Mooruk, with its middle turbinal, 



simple upper turbinal semi-scroll, and posterior part of inferior turbinal; 



4 diameters. 

 Fig. 18. Ditto, section through anterior part of ethmoid of the same, and posterior part 



of inferior turbinal ; 4 diameters. 

 Fig. 19. Ditto, section through widest part of nasals, and fullest part of inferior 



turbinals; 4 diameters. 

 Fig. 20. Ditto, section through the hinder part of ethmoid of the Mooruk, and through 



frontals and anterior sphenoid ; 4 diameters. 



PLATE XI. 



Fig. 1. Dromceus irroratus, "A." Side view of skull; 2 diameters: i.e.s. intereth- 

 moidal space. 



Fig. 2. Ditto, basal view; 2 diameters. 



Fig. 3. Ditto, upper view ; 2 diameters. 



Fig. 4. Ditto, ditto, end view ; 2 diameters. 



Fig. 5. Upper view of part of lower jaw of the same Emu; 4 diameters: sp. splenial. 



Fig. 6. Ditto, ditto, proximal end seen from above; 4 diameters: c.r. coronoid. 



Fig. 7. Ditto, obliquely basal view of hinder part of skull ; 4 diameters : m.p.g. meta- 

 pterygoid ; eu. Eustachian groove ; sy. symplectic, with its anterior and 

 posterior rays given off near the shaft of the " stapes." 



Fig. 8. Ditto, OS hyoides ; 2 diameters. 



Fig. 9. End view of skull of '■'■ Brommis B. ;" 1^ diameter. 



Fig. 10. Dromceus Novce-Hollandice (" B."). Part of skull and face, side view ; 3 dia- 

 meters : ep. epiotic ; m.p.q^. metapterygoid process of os quadratum. 



