THE UNGULATA. 341 



dible are situated upon the inner face of tlie very higli per- 

 pendicular part of tlie ramus. The teeth are trilobed, two 

 deep grooves excavating their inner and their oixter sur- 

 faces. And, as the crowns of those of each jaw are placed 

 opposite each other, they are worn flat. 



The last cervical and the anterior dorsal vertebrae are 

 ankylosed together into a single " tri-vertebral" bone, which 

 moves by a hinge joint upon the third dorsal. This and 

 the succeeding dorso-lumbar vertebi-as are immovably 

 united, and, for the most part, ankylosed, together. The 

 head of the first rib is engaged in the socket furnished to 

 it by the tri-vertebral bone in such a manner as to be 

 immovable, and the rib is not flat, but rounded and co- 

 lumnar. 



In the carpus, the cuneiform bone articulates with the 

 fourth, as well as with the fifth metacarpal, the latter bone 

 being entirely supported by the cuneiform. The metacarpals 

 and phalanges are all very short and broad. The pollex is 

 rudimentary, while the fifth digit is fully developed. 



The supra-condyloid ridge of the femur is not distinct 

 from the third trochanter, even if the latter can be said to 

 exist at all. The metatarsal bones are as broad as they are 

 long, or broader ; and, as in the fore foot, the majority of 

 the phalanges are comparatively short and ti-uncated. 



The Non-decidtjate Mammalia. — I. Ungulata. — A 

 large number of the non-deciduate Mammalia are con- 

 veniently comprehended under the title of the Ungulata, 

 though it may be open to question whether the group 

 thus named represents a single order, or more than one. 



In all the Ungulata the placenta is either difi'use, that is 

 to say, the villi are scattered evenly over the surface of the 

 chorion ; or it is cotyledonary, in which latter case, the villi 

 are accumulated in distinct patches on the chorion. These 

 patches are called cotyledons. 



All Ungulata have milk teeth, succeeded vertically by 

 teeth of the permanent set. The teeth consist of enamel, 

 dentine and cement, and the grinders have broad crowns, 

 with tuberculated, ridged, or folded enamel. 



