346 SYNOPSIS OF THE VEKTEBRATB FAUNA OF THE PUERCO SERIES. 



than wide. The cuboid facet is continuous, at a i-ight angle with the navicular facet. 

 The metatarsal facet is simple, and is anteroposteriorly concave. There are two distal 

 mesocuneiform facets, and one proximal which is turned down for a short distance in 

 front. 



The Dissacus navajovius is a smaller species than any of the other Mesonychidse, 

 and is especially interesting in view of the ancestral characters which it displays. 

 It shows that the specialization of the extremities which has occurred in the Car- 

 nivora has taken place in this line also, in the jirogressive digitigradism ; the reduction 

 of the digits ; the development of a trochlea of the ankle-joint ; and the loss of 

 cusps from the molar teeth. 



3Ieasurements. M. 



Length of base of paradiapophysis of atlas OIG 



" " odontoid process of axis 009 



" " atlantal facet of axis 013 



" " centrum of lumbar vertebriB 018 



^ anteroposterior 020 



Diameters glenoid cavity of scapula < 



^ transverse 014 



Transverse diameter condyles humerus in front 017 



Anteroposterior diameter of flange of do 015 



Length of olecranon 028 



Depth olecranon at middle 015 



" ulna at glenoid cavity 013 



" ulna at middle 013 



I vertical 0085 



transverse 015 



Diameter of head of femur 017 



. ( anteroposterior 014 



Diameters distal end of tibia { 



I transverse 017 



Length of astragalus 023 



Greatest width of astragalus 018 



I anteroposterior 014 



' transverse Oil 



Transverse diameter navicular facet do 018 



cuboid " " 002 



Length of calcaneum 043 



" " tubercalcis 035 



Width calcaneum at sustentaculum 0185 



vertical 0085 



transverse 013 



Dei)th of calcaneum just lichiud cuboid facet 013 



Length of cuboid 018 



„.,,,. . . , ., ^ anteroposterior 010 



Distal diameters of cuboid { 



i transverse 010 



Diameters of head of radius 



Diameters trochlea of astragalus 



Diameters of cuboid facet ■ 



r longitudinal in front 008 



Diameters of ectocunr'iform I anteroposterior 010 



[ transverse distally OOlj 



