HIPPOPOTAMUS. 



19 



individuals ; they decrease gradually in length as far as the anticlinal vertebra, 

 which is the last but one. The longest spines are considerably shorter than those 

 of a rhinoceros of corresponding size. The inclination of the neural spines from the 

 vertical gradually increases from the first, where the spine is almost vertical, to the 



Pig. 3. — Cervical vertebrae. A 4th, front view ; Q 5th, posterior view ; Q 3rd, right side view ; fj 6th, left side 

 view : £ 7th, front view. All \ natural size. All from Harrington and preserved in the Sedgwick Museum, 

 Cambridge. «, neural spine; 6, neural canal: c, prezygapophysis : d, postzygapophysis ; e, transverse process ; 

 /, inferior lamella of transverse process ; g, vertebrarterial canal ; h, anterior face of centrum ; i, posterior face 

 of centrum. 



eighth. The short stout spines of the last four or five vertebrae gradually become 

 more and more nearly vertical. The centra are nearly cylindrical, have flat 

 articulating surfaces, and are very uniform in length. The zygapophyses lie 

 horizontally as far back as the 10th or 11th vertebras, after which they become 

 almost vertical, as in the lumbars. 



