3OO PATAGONIAN EXPEDITIONS: PALEONTOLOGY. 



MEASUREMENTS. 



Amegh. Coll. No. 15,344. No. 15,524. 



Skull, length in median basal line .099 



" " condyle to anterior nares 120 .118 



Cranium, length to edge of orbit 100 .094 .089 



Face, length orbit to anterior nares . . % 024 .025 



Skull, width at zygomatic processes .047 .048 



" " " postorbital constriction .029 .030 



Occiput, height 041 .035 .039 



width at base .047 .05 1 



Zygomatic arch, length .070 



Palate, length in median line .042 



width at 1 .019 



"1 .014 .016 



"A .0115 .012 



Amegh. Coll. No. 15,39 f. No. 15,901. 



Mandible, length from condyle 07 5 



" of predental beak 014 



depth below ^ 026 .024 .029 



thickness below ^ .013 .015 



depth behind ? 021 .019 .023 



height of coronoid 053 .050 



A specimen (No. 9,244, Plate LIU, fig. 8) in the American Museum of 

 Natural History, consisting of the last two thoracic vertebrae, the entire 

 lumbar series, sacrum and pelvis, may be provisionally referred to this 

 species. It may, however, be assignable to a large species of the nearly 

 allied genus Pelecyodon. The two thoracic vertebrae have short but 

 heavy centra, with small foramina opening on the ventral side, very short 

 neural spines, which are strongly inclined backward and thickened at the 

 tip, especially on the penultimate vertebra; the very short transverse 

 processes bear facets for the rib-tubercles, even on the last thoracic ; ac- 

 cessory articular processes are found only in the form of a pair of small 

 additional postzygapophyses on the last vertebra, a very marked contrast 

 to Hapahps ; the metapophyses also are much smaller than in the latter. 



There are five lumbars, a larger number than has been observed in any 

 other contemporary species of the Gravigrada. The centra of these ver- 

 tebras increase in length to the third and then diminish, but become broader 

 and more depressed to the last ; the ventral foramina are conspicuous on 

 all of them, despite the completely adult state of the animal, and are espec- 

 ially large on the second and fifth. The neural spines are remarkably 



