18 



must be considered as answering to the sub-orbital foramen iu otlier 

 animals; although, as Cuvier says, it is in these Cetacea, more 

 correctly speaking, super-orlital. 



The posterior angle of the orbit is occupied by the point of 

 the zygomatic apophyse of the temporal ; but this does not 

 quite join the post-orbital apophyse of the frontal, so that the 

 orbit is, as it "were, open at this place. 



The inferior rim of the orbit is formed by a thick and 

 cylindrical jugal, of which the fore part is dilated into an oblong 

 plate, which partly closes the orbit in front. 



The fossa temporalis is rather deep, of a roundish form, but 

 not distinguished by any crest from the rest of the occiput. The 

 zygomatic part of the temporal is shaped like a thick and short 

 cone. Beaching to the orbit it alone forms the zygomatic arch, 

 as in the dolj^hins. The occipital bone is vertical, and forms all 

 the posterior face of that semicircular wall which is so singular 

 a characteristic of the back of the head. The lower edge of this 

 occipital bone is divided on each side by a notch into two lobes 

 of which the external one represents the mastoid apophyse. 



OF THE OS HYOIDES. 



When the intestines and other soft portions of the animal 

 were about to be towed to sea, and cast adrift, I desired the 

 men carefully to explore the masses of flesh ; the result was 

 fortunate, for they had not made use of their spades many 

 minutes before they struck against some hard substances in 

 one mass, Avhich, on examination proved to be the parts of 

 the OS hyoides. This organ, in cetaceous animals, is generally 

 composed of three bones — two lateral, which are the styloi- 

 deans ; and a central one, which is the true os hyoides, and 

 which is often separable into three. The styloideans, or styloid 

 processes, are attached by a cartilage to that lobe of the occipital 

 which represents the mastoid process. The os hyoides itself has 

 somewhat of a crescent form, having at the convex and anterior 



