EDENTATA OF THE SANTA CRUZ BEDS. 



II 



mally in a prominent, incurved hook. The manus is always pentadactyl 

 and all the digits bear claws ; in all known species the second digit is the 

 longest of the series. In only one genus, Stenotatus, are any of the 

 phalanges coossified. The lingual phalanges are always long, heavy, 

 decurved and pointed, and were evidently well adapted to burrowing 

 habits. 



The pelvis varies considerably in the different genera, but does not 

 depart widely from the modern type. The femur is elongate and has a 



IV 



II! 



'in 



FIG. 4. 



Right manus of Santa Cruz armadillos, x f . a, Prozaedius exilis ; b, Stenotatus patagonicus ; 

 c, Proeutatus robustus. 



very prominent great trochanter, which in Proeutatus reaches remarkable 

 proportions, the third trochanter is. also well developed in all cases. As 

 in the recent armadillos, the tibia and fibula are invariably coossified at 

 both the proximal and the distal ends. Like the manus, the pes is always 

 pentadactyl, though in some of the genera, and especially in Peltephilus, 

 the lateral digits are much reduced. The ungual phalanges are usually 

 much shorter and broader than those of the manus and are often more 

 like hoofs than claws. 



In size, there is much variety among the Santa Cruz armadillos, rang- 

 ing from the minute Prozaedius to Proeutatus, some species of which are 

 larger than any existing armadillo, except Priodontes, while the very 

 incompletely known Peltephilus grandis may have equalled or even sur- 

 passed the latter. 



