100 ON THE OSTEOLOGY OF BIRDS. [Feb. 15, 



far foniard as the 1st thoracic ^ertebl■a. The last sternal rib has a 

 posterior expansion situated immediately behind the articulation 

 with its dorsal element. 



List of Woeks referred to. 



1. Beddard, F. E. — " On the Anatomy of Phaethon." P. Z. S. 



1897. 



2. Beddakd, F. E.— " Note upon Intercentrti in the Vertebral 

 Column of Birds." P. Z. S. 1897. 



3. Brandt, J. F. — " Beitrage ziir Keun. u. d. Naturgesehich. der 



Vdgel." Mem. Acad. Wei. St. Petersbourg, ser. vi. 



4. Eyton,T. C— Osteologia Avium. London, 1867, pis. 5, 6, 7 L, 



pp. 216-220. 



5. Forbes, W. A.— Collected Scientific Papers, pp. 216, 336. 



6. FuREitiNGER. — ' Untersuch. zur Morphol. und Systemat. der 



Vogel.' II. Allgem. Theil. S. 1031. 



7. Gadow, H.— Bronn's Thier-Eeich, Bd. vi., Vdgel, 1891 : 

 Anatom. Theil. 



8. Gadow, H.— Ibid., Syst. Tbeil, 1893. 



9. Garrod, H. — Collected Scientific Papers, 1881. 



10. HuxLET, T. H.— " On the Classification of Birds." P. Z. S. 

 1867. 



11. Lydekker, E.— Cat. Foss. Birds Brit. Mus., 1891. 



12. Mivart, St. G.— " On the Axial Skeleton of the Pelecanidse." 

 Trans. Z. S. 1878. 



13. Shueeldt, E. W. — " Eemarlis on the Osteology of PJialacro- 

 corax bicristatiis." Science, ii. p. 640. 



14. Shueeldt, E.W. — " Osteology of the Cormorant." Science, iii. 

 p. 143. 



15. Shtjeeldt, E. W. — " Observations on the Osteology of the 

 Tubinares and Steganopodes." P. U. S. Nat. Mus. 1888, p. 253. 



16. Walker, M. L.— "On the Form of the Quadrate Bone in 

 Birds." Studies from the Museum of Zoology in University 

 College, Dundee, 1890, pp. 5-7, figs. 8, 9, 10.' 



EXPLANATION OP THE PLATES. 



£. pi. = Basitemporal plate. P(. = Pterygoid. 



ilfojo.=:Maxillo-palatine process. §= Quadrate. 



JVs. = Nasal septum. /'''= Vomer. 

 P= Palatine. 



Plate VII. 



Fig. 1. Ventral view of the skull of Frcgata arid, sbowiiig the form of the 

 basitemporal plate, the maxillo-palatine processes, and the ankylosis of 

 the posterior ends of the palatines. 



Fig. 2. Ventral view of the skull of Phaethon flavirostris, showing the same as 

 fig. 1. The postei'ior ends of the palatines, though closely approxi- 

 mated, are not fused. 



Fig. 3. Ventral view of the skull of Phalacrocorax carbo showing the same as 

 the above. The palatines are here more or less fused from the 

 posterior narial aperture backwards to the pterygoids. There is no 



