62 PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 



The pes (Plate XIV, fig. 6) has much resemblance to that of Dasypns. 

 The astragalus is stout and very broad, decidedly more so than in Stego- 

 therium, while the trochlea is less distinctly grooved and has a less raised 

 inner border; a deep sulcus invades the outer condyle from behind. 

 From the outer side arises a prominent projection, which bears a concave, 

 dorsally presenting facet for the fibula. The external calcaneal facet is 

 very concave and oblique and is separated by a deep groove from the 

 large and slightly convex sustentacular facet. The neck is short, broad 

 and depressed and bears on its dorsal side a facet, which is in contact 

 with the tibia only when the foot is in extreme flexion ; the distal head 

 has a greater dorso-plantar diameter than in Stegotherium. The calca- 

 neum is large and has quite an elongate tuber, its principal distinction from 

 that of Cabassous, which otherwise it much resembles ; this tuber is much 

 depressed and flattened, far more so than in Dasypus, and is in very 

 strong contrast to the laterally compressed tuber of Stegotherium and 

 Tatu; it broadens rapidly to the free end, though hardly so much or so 

 abruptly as in Cabassous; the proximal end has a distinct internal tubercle 

 and, on the plantar side, a broad tendinal sulcus. The distal portion of 

 the calcaneum is short, but very wide; the external astragalar facet is 

 broad and simply convex ; it is less oblique in position and reflected 

 farther upon the dorsal side of the tuber than in Stegotherium, and it does 

 not project so far outward as in the latter, while the fibular facet presents 

 laterally, instead of dorsally. The sustentaculum is very large and only 

 partially occupied by the facet, and the tubercle for the attachment of the 

 lateral ligament is very prominent and distinctly grooved. The cuboid 

 facet is broad transversely and short in the dorso-plantar diameter. 



An accessory ossicle is attached to the tibial side of the navicular, prox- 

 imal to the entocuneiform ; it is large and compressed proximally, con- 

 tracting to a blunt point distally, and resembling that of the recent 

 Zaedyus in form. 



The cuboid is broad distally, narrowing proximally and thus has a 

 somewhat pyramidal form, for the strongly convex calcaneal facet is very 

 oblique and external, rather than proximal, in position. 



The other tarsal bones, the navicular and cuneiforms, are of the usual 

 armadillo type and require no particular description. 



Metatarsal I is short and heavy ; in length it almost exactly equals 

 metacarpal I, but is broader and more depressed ; the proximal end is the 



