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PROCEEDINGS OF THE NATIONAL. MUSEUM 



vol. 84 



tendinal impression on inner posterior angle narrower and more 

 heavily impressed on the shaft in its upper portion. 



Description.— Tyi^e, U.S.N.M. no. 13897, distal end of right tarso- 

 metatarsus, from Miocene of Quarry A in sec. 29, T. 31, R. 47, Dawes 

 County, Nebr., collected in 1934 by Ted Galusha. Outer trochlea 

 narrow, compressed laterally, with a thin plate projecting posteriorly, 

 elliptical in outline when viewed from the side; inner face much 

 excavated, intertroclilear sulcus separating it from middle trochlea 

 distinctly wider than that between internal and middle trochlea; 

 middle troclilea nearly circular in outline when viewed from the side, 

 relatively strong and robust; distinctly elevated from the level of the 

 shaft both posteriorly and anteriorly, with a pronounced groove 

 extending completely around the articular surface; both faces much 



excavated ; inner trochlea 

 compressed, with a dis- 

 tinct impression in cen- 

 ter of outer face, beyond 

 which the bone extends 

 as a narrowed projection 

 triangular in general 

 outline ; inner face much 

 excavated ; intertroclilear 

 sulcus between it and 

 middle trochlea decided- 

 ly narroAved; lower end 

 of shaft flattened and 

 expanded, forming a 

 broad base from which project the trochlea ; inferior foramen of good 

 size, located relatively low on the shaft, with a slight depression 

 around it behind, and a distinct groove leading into it from above 

 on the anterior face; body of shaft strong and robust, with outer 

 face plain, the boundaries being sharp-ridged both in front and in 

 back; a strongly impressed tendinal groove on inner angle; posterior 

 face of shaft with a broad, shallow groove above; impression for 

 articulation of hallux strongly marked; anterior face of shaft a 

 somewhat irregular plane sloping toward the inner margin. Bone 

 well fossilized, dull gray in color, whiter on the trochlea. 



Measurements. — Smallest transverse breadth of shaft, 9.7 mm; 

 transverse breadth across troclilea, 20.4 mm. 



Remarlcs. — This species seems to have been one witli strong and 

 robust foot, indicating a distinctly predatory type of life. The short, 

 heavy form of the inner trochlea, witli the relatively slightly project- 

 ing wing, and the relatively large size of the middle trochlea com- 



FiGUKE 13. — Palaeohorus howardae, new species : Distal 

 end of tarso-metatarsus of type (U.S.N.M. no. 13897). 

 About natural size. 



