EDENTATA OF THE SANTA CRUZ BEDS. IOI 



MEASUREMENTS. 



Metatarsal II, length 033 Ungual, digit I, length 009 



" " width of proximal end 008 " " " width of proximal end. .0045 



Metatarsal III, length 034 " " II, length oi 25 



" " width of proximal end. .. .010 " " " width of proximal end. .007 



Metatarsal IV, length 033 " " III, length 013 



" " width of proximal end 007 " " " width of proximal end. .0085 



Metatarsal V, length 008 " " IV, length 013 



" " width of proximal end 006 " " " width of proximal end. .007 



First phalanx, digit I, length 009 " " V, length oio 



" "II, " 012 " " " width of proximal end. .0065 



First phalanx, digit II, width of prox- Digit I, length 031 



imal end 007 " II, " 065 



First phalanx, digit III, length 009 " III, " 065 



" " " IV, length 008 " IV, " 060 



" " " V, length 004 " V, " 027 



PELTEPHILUS PUMILUS Ameghino. 



(Plate XVI, figs. 3-5.) 



Peltephilus pmnilus Amegh. ; Enum. sistematica, etc., 1887, p. 25. 

 Peltephilus pumilus Moreno and Mercerat ; Rev. del Museo de La Plata, 



T. II, 1891, p. 82. 

 Peltephilus strepens Lydekker, in part ; Anales del Museo de La Plata, 



T. Ill, 1894, p. 70. 



In size, this is one of the smaller species, though it is not much inferior 

 to P. ferox. The dentition has certain characteristic features : - is placed 

 transversely in the premaxilla, so as to be almost concealed in side-view 

 by -, which is the most prominent of the teeth ; - is lower, but larger in 

 the other dimensions. From - to - inclusive each tooth has on the outer 

 side a vertical groove near the hinder border, which is thus raised into 

 an inconspicuous pillar. 



The cranium is quite convex in the antero-posterior direction and the 

 descent from the forehead to the rostrum is quite abrupt ; the rostrum 

 itself is relatively short. The sagittal crest is feebly developed and is 

 accompanied to the coronal suture by a narrow, faintly marked sagittal 

 area, the borders of which become continuous with the still more obscure 

 temporal ridges. Anteriorly, the tubular prolongation of the nasals and 

 the ascending rami of the premaxillaries are short and the median anterior 

 spine-like process from the line of suture is very small. 



