[Annals N. Y, Acad. Sci., Vol. XXVII, pp. 193-203, Pll. VII-XIV. 

 9 August, 1916] 



PEELIMI^ARY EEPOET ON FOSSIL MAMMALS FEOM POETO 



EICO, WITH DESCEIPTIONS OP A NEW GENUS OF 



GEOUND SLOTH AND TWO NEW GENEEA 



OP HYSTEICOMOEPH EODENTS ^ 



By H. E. Anthony .<v ..i^*^'^'' '^^i/fr> 

 {Presented ly title before the Academy!^ ^'P'R^j^^)|9|7 t 



CONTENTS \ '^ . ^C,* / 



Introduction ^^- r'^'}'t 



Systematic treatment 195 



New genus of ground sloth 195 



Description of Acratocnus odontrigonus 195 



Skull 195 



Measurements of cranium 196 



Mandibular ramus 196 



Measurements of ramus 196 



Humerus 196 



Radius 197 



Unguinal phalanx 197 



Femur , 197 



Tibia 197 



Fibula 197 



Calcaneum 198 



Vertebrae 198 



Remarks 198 



New genus of hystricomorph \ 199 



Description of Elasmodontomi/s ol)liquus . . . . < 200 



Skull 20O 



Dentition 200 



Measurements 201 



Limb bones and trunk skeleton 201 



Remarks ~. 201 



Second new genus of hystricomorph 202 



Description of Heteropsomys insulans 202 



Skull • 202 



Dentition 203 



Measurements ■ 203 



Remarks 203 



1 Manuscript i-eceived by the Editor, G June, 191G. 



(193) 



