AMERICAN WHITE PELICAN. 



31 



parallel to the mandible, and about half an inch distant from it, sending off 

 branches at intervals. The sac is plentifully supplied with blood-vessels. 



The nasal cavity is of an oblong form, 1 inch and 5 twelfths in length, 

 passing obliquely backwards and upwards from the aperture of the posterior 

 nares, and opening externally by curving forwards; its greatest diameter 5 

 twelfths, in its lower third 3 twelfths, and so continuing until it expands 

 into the inferior slit-like aperture, which is 8 twelfths long. The cavity of 

 the nose is thus small, and the olfactory nerve, which passes out from the 

 anterior part of the brain, is a slender filament, about | of a twelfth in 

 diameter. It runs at first through a bony tube, then passes along the bony 

 septum of the orbits, in contact for a short space with the superior maxillary 

 nerve of the fifth pair, which at its commencement makes a great curve 

 upwards, and crosses the 

 orbit to enter the maxillary ** 



cavity, which has no com- 

 munication with the olfac- 

 tory. Fig. 2 represents the 

 sternum viewed from be- 

 fore. It is remarkable 

 chiefly for its great breadth 

 and convexity. Its sides, 

 a, b, c, d, are nearly pa- 

 rallel; its posterior margin 

 broad, with two shallow 

 notches, e, f, separated by 

 a short conical obtuse me- 

 dian process. The crest or 

 ridge, h, i, is carried for- 

 ward in front, where it is 

 only, however, of moderate 

 height, and is not continued 

 to the posterior extremity, 

 but terminates at i, in the 

 most convex part. The 

 coracoid bones, i, i, are ex- 

 tremely large, very broad 

 at their lower part, and 

 having a deep groove and 

 thin elongated process, j, 

 at the upper for the tendon 

 of the pectoralis medius, 



