542 



THE MAMMALIA OF THE UINTA FORMATION. 



1. The Tapir Series. 



In Isectolophus (Ko. 10,401, Piinc. Coll.), from the Uinta beds, we have a genus 

 which is in or near the line of the true tapirs. It is represented by the almost com- 

 plete carpus and a single element of the tai-sus, the cuboid. (See full previous de- 

 scription, also PI. X, Fig. 3.) 



The carjjus. The elements of the carpus are broad relatively to their height. 

 The scaphoid has a horizontal trapezoid facet and slightl}' oblique magnum facet ; 

 thus its main weight is borne by the former bone. The lunar is lai-ge and has a 

 slightly larger unciform than magnum contact, but it may be said to rest equally 

 upon these bones. The cuneiform divides the upper surface of the unciform with the 

 lunar. The magnum articulates with the scaphoid, lunar, trapezoid, unciform, and 

 distally with the metacarpals II and III. The carpo-metacarpal articulation is of the 

 usual alternating order. The unciform has inferior facets for metacarpals iv and v. 



The tarsus. The cuboid is subquadrate in shape when viewed from in front and 

 from above and proximally has a small astragalar facet. 



No intermediate forms have been described. The manus and pes of the recent 

 Tapirus indiciis do not show a very wide divei'gence from the type above described. 

 The scaphoid is enlaigod posterioily and besides its trapezium facet has subequal 

 and horizontal tiapezoid and magnum facets. The lunar has a relatively larger 

 unciform facet, but still rests directly upon the magnum by a horizontal facet which 

 is variable in width. The cuboid is subquadrate and partly supports the astragalus. 

 The tarso-metatarsal articulation varies in ditierent species. In T. indicus both mts, 

 II and IV abut against the ectocuneiform. 



/inhelonSy 



DiAC. 9. — Tlif (lisplafcmonl of llie bones of the niiinus in llic Un.ffulata, II. Su» scrofa, illnslraling tlif typical 

 adaptive disiilaci'iiu'iit in the Aiiiodiictylii. TiUtnothvrium {MnimUis). fiont original in ll;uvanl collection; AiieJiit/ie- 

 rium aurelianeme, after Kowalevsky ; AphHops, fioin oriijinal in Harvaid collection. The oblique arrows indicate the 

 direction of dis|ilaccnient ; the double \i'rlical arrows indicate the niesaxial line of the foot. 



