GLIRES OF THE SANTA CRUZ BEDS. 



447 



inner side of the ramus more concave. The condyle resembles that of 

 Viscaccia, except in being narrower, and the coronoid rises more nearly to 

 the level of the condyle, though, owing to the shallowness of the sigmoid 

 notch, its freely projecting portion is much shorter. 



The cervical vertebrae indicate a longer neck, proportionately to the size 

 of the head, than in Viscaccia. The atlas, which is broad and low, has a 

 prominent hypapophysis, which is not present in the modern genus. The 

 axis is broad in front, very narrow behind, with posterior face which is 

 dorso-ventrally concave ; so much of the broken neural spine as remains 

 resembles that of the recent genus, except that it is less inclined back- 

 ward. The other cervicals have oblique faces and the posterior face, as 

 in the axis, is dorso-ventrally concave ; on the third, fourth and fifth verte- 

 brae, at least, the spine is obsolete. 



It will be unnecessary to repeat here the description of the limb bones 

 given in the accouut of the genus. 



Upper dentition, length p4 m-S. 



P-i, length (t. e., antero-posterior diam- 

 eter) 



P-*-, width (i. e., transverse diameter) . . 



Mi, length 



" width 



Lower dentition, length 



MEASUREMENTS. 

 .017 



P T , length 



" width 



Mg-, length 



" width 



Occiput, height 



" width at base 



Tympanic bulla, length 



Zygomatic arch, length 



Mandible, length from condyle . . . 



" depth at p^ 



" thickness at p^ 



" height of condyle 



" " " coronoid 



Axis, length, including odontoid. 



Axis, length excluding odontoid 009 



" width of anterior face on 



.003 5 Third cervical, length of centrum 007 



.005 Fourth " " " " 006 



.006 Fifth " " " " 008 



.004 Humerus, width of distal end oil 



.035 " " " trochlea 008 



.018 Ulna, width at sigmoid notch 005 



.005 " " " distal end 002 



.004 Radius, approximate length 042 



.006 " width of proximal end 0063 



.004 Metacarpal III, length 013 



.020 " proximal width 003 



.020 " distal width 003 



.014 Patella, length oio 



.032 " width 005 



.047 Calcaneum, length 017 



.010 " " of tuber 007 



.006 Metatarsal III, proximal width 0035 



.020 " " distal width 004 



.018 

 .013 



