104 Mr. Brookes on a new Genus of the Order Rodentia. 



Feet. Inches. 



From the atlas to the tuber ischii 1 0-|- ' 



crista ilii to the tuber ischii .... 4 



Length of the fore extremity from the head of the 



OS brachii to the end of the longest nail ..06 

 from the head of the os brachii to the ex- 

 ternal condyle ^^ 



' from the end of the olecranon to that of 



the longest nail . 4^ 



of the hinder extremity 1 0^ 



from the trochanter major to the lower 



portion of the external condyle of the femur 3^ 



from the upper surface of the tibia along 



the fibula to the malleolus externus ... 44- 

 from the end of the os calcis to the ex- 

 treme end of the middle toe . . ... 4^ 

 The occipital diameter of the cranium of the Lagostomus is 

 1 inch and fths, and its diameter between the ascending por- 

 tions of the zygoma 1 inch and fths. The corresponding mea- 

 surements in the Dipus are respectively ^ths and -fths of an 

 inch. 



EXPLANATION OF TAB. IX. 



Fig. a. Lagostomus trichodactyluSf^ 



b. Skeleton of the same, n ir ^i. xt ^ i • ^ 

 ^^. . ' y Half the Natural size. 



c. Upper jaw, j 



d. Under jaw, J 



e. Crown of the second molar tooth of the" 



left side of the lower jaw, I , 



/. Ditto of the last molar tooth of the right 

 side of the upper jaw, 



VII. De- 



