LIST OF TEXT ILLUSTRATIONS. xi 



Fig. 39. Skulls of Octodontidse, top view, a, Myocastor coypus, x f ; b, Capromys four- 



nicri, x \ ; c, Ncorcomys australis, x \ . . . . . . 393 



Fig. 40. Grinding teeth of Viscaccia chilensis, crown view, x \. a, right upper teeth ; 



b, right lower teeth .......... 434 



Fig. 41. Skull of Viscaccia chilensis, x \. a, left side; b, top . . . . . 435 



Fig. 42. Type of Prolagostomus obliquidcns ; mandible, crown view, x 2 . . . 456 

 Fig. 43. Grinding teeth of Caviidas. a, right upper teeth ; a', right lower teeth of Doli- 



clwtis magellanica, x \ ', b, right upper teeth ; b 1 ', right lower teeth of Cavia 



cobaya, x \ 461 



Fig. 44. Eocardia sp., teeth of young individuals, lower right side, external and crown 



views, x \ . a, Dp f in very young stage ; b, Dp 3 , m T and ^, later stage. 



A. M. N. H 462 



Fig. 45. Skulls of Caviidse, leftside, a, Dolichotis magellanica, x \ ; b, Cavia cobaya, 



X \ ', Eocardia cxcavata, x \ . . . . . . . . 464 



Fig. 46. Eocardia montana, lower grinding teeth, x \. a, right side, crown view ; b, 



right side, external and crown views, A. M. N. H. ; c, left side, crown view, 



A. M. N. H 473 



Fig. 47. Eocardia excavata, lower grinding teeth, external and crown views, x \. a, 



right side ; b, left side of same individual (No. 15,211) . . . . 475 

 Fig. 48. Eocardia modica, left lower grinding teeth, external and crown views, x \ . 



A. M. N. H 476 



Fig. 49. Type of Eocardia petersoni, left mandibular ramus, crown view, x \ . 477 



