CORVID^. 7 



D. In the interorbital septum is a large fenestra situated iniine- 



diatelj in front of the optic foranuMi, and rather more than 

 twice the diameter of the hitter. 



E. Zygomatic process of frontal and stiuamosal well-marked 



and nearly equal. 

 " All the Corvidcv possess the s/jthoninni, one upon eitlu^r side 

 the skull, it being a curved osseous tube, describ(Ml Ijy Nitzsch, 

 which conducts the air from the tympanic cavity to the lower 

 jaw." {Slwfeldt.) 



Genus TRYPANOCORAX. 



Suudevall, Av. Meth. Tent. p. 43 (1872). 



Trypanocorax frugilegus. 



CorvKs frugilegm, Linnaeus, Syst. Nat. i. p. 150 (L76G) ; Eytou, 



Ostcol. Av. p. 147 (1867). 

 Trypanocorax friMiilegus, Sharpe, Cat. 13. Brit. Mas. iii. p. ( 1877). 



The Common Eook. 



Hah. Europe, wintering in N.W. India. 



1. Skeleton. 0. C. 1553 a. Yarrell Collection. 



2. Skeleton. 0. C. 1553 d. 



Presented by Professor Flower, C.B., F.R.S. 



3. Skeleton of male. From Uxbridge. 



Presented hy Mr. T. DevoHsliire. 



4. Skeleton of female. From Uxbridge. 



Presented hy Mr. T. DevonsJtire. 



5. Sternum (with furcula, right coracoid, and scapida). 



S. S. 830. Purchased. 



6. Skull. O.C. 1553 F. Presented hy IT. J. Bon,, or, Ks,j. 



7. Skull. From Southend. 0. C. 1553 E. 



Presented hy Mr. J. Marie. 



8. Skull, with malformed mandibles. 0. C. 1553 C (Figured 



in Yarrell's ' British Birds,' ii. p. 90.) 



9. Skull, 0. C. 1553. Ilni,t,-rin„. 



10. Skid! of nuile. From GeniKiiiy. P,ir(l,<is,d. 



11. Skull ol' I'riiialc. F'-oni ( JennauN . Piirc/iascd. 



