ANATOMY OF MEGAPTERA LONGIMANA. 179 



behind to a height of 1 inch above the level of the rest of the 

 upper border of the neck. Viewed from above, it is about 2| 

 inches th-ick at the top, narrowing forwards, with a smooth 

 interval, for a hand's breadth, between the elevation and the 

 coronoid process. Backwards the rough surface is suddenly 

 narrowed by the notching to form the dental foramen. The 

 roughness extends down on the inside for 8 inches, in front of 

 the dental foramen, most marked on its anterior 4 inches, where 

 the wall rises as a low mound. The roughness of this post- coronoid 

 elevation is not that of cartilage-covered bone, but as of bone 

 to which tendon or ligament had been attached. The same of 

 the pre-coronoid thickening, but the roughness is less marked. 



[In B. musculus there is no post-coronoid upward elevation, but on 

 the inside, at this part of the neck, the inward elevation and rough- 

 ness, over the dental canal, is more marked than in Megaptei'a. It 

 goes down, for 2| inches, only to below the level of the middle of the 

 spine, and ends by a well-defined edge. The upper border of the neck 

 at this part, though not forming an upward elevation, is flattened and 

 rough (with a breadth of 1 inch) for 6 inches, being the space between 

 the dental foramen and the coronoid process, the flattening reaching 

 for 2 inches up on the hinder border of the coronoid process. This 

 flattening and roughness of the border here contrasts strongly with 

 the smoothness of this part of the border in Megaptera.] 



Direction of the Neck and Position of the Dental Foramen. 

 — The place where the axis of the body and the axis of the 

 neck meet is farther back in Megaptera than in B. musculus. 

 The distance between the back of the condyle and the coronoid 

 process is the same in both (25 inches), but the dental foramen 

 is much farther back in Megaj^tera (11| inches from the con- 

 dyle) than in B. musculus (16 inches). The axes of the body 

 and neck meet at the dental foramen. This gives a very 

 different form to the necks. The outward convexity of the 

 body in B. musculus ceases just behind the coronoid process, 

 and sharply, so that the outer surface of the neck is deeply 

 concave longitudinally (concavity between the coronoid part 

 and the tuberosity below the condyle, 3 inches deep) ; while in 

 Megaptera the outward convexity of the body goes back to 

 about the middle of the neck, and the concavity is less (about 

 2 inches deep). 



There is also much greater torsion of the neck in B. mus- 



