544 



CHORD ATA. 



The skull is of very j^eculiar shape and construction. 

 The cranial part is almost globose in shape, and the facial 

 is long, flat and tapering, forming the so-called '* rostrum." 

 It is not difficult to get at least some insight into the 

 reasons underlying these peculiarities. If we recall the 



l^^ig- 375.— Section of Skull of Young Dolphin {Globiccephalus nicla 



(After Flower.) 



PI, Palatine. Per, Internal nares. Pt, Pterygoid. PS, Presphenoid. BS, Basisph< 

 oid. ^6", Alisphenoid. F*?, Vomer. J/;i-, Maxilla. /^iJ/;r, Premaxilla. 71/^, Mesethmo 

 an. External nares. Na^, Nasal. IP, Interparietal. P'r, Frontal. Pa, Parietal. ^ 6" 

 Supraoccipital. ExO, Exoccipital. BO, Basioccipital. Sq, Squamosal. Per, Periot 

 th, Hyoid. cd. Condyle, a, angle, s. Symphysis. 



facial part of any of our terrestrial animals we find that 

 it subserves two functions. The under-surface and lower 

 part of it, forming the buccal chamber, is connected with 

 the alimentary function ; it bears the teeth and forms the 

 palate. The upper part contains the large and complex 

 nasal chambers, access to which is obtained by the 



