TARSO-METATARSUS OF HESPERORNIS. 97 



tarso-inetatarsal bone is a striking character, and may possibly be an 

 indication of sex. 



The tarso-metatarsal of Hesperomis gracilis is similar in its general 

 character to the corresponding bone in Hesperomis regalis, but is of more 

 slender proportions. 



The measurement of the tarso-metatarsal bones of the three knoTrn 

 species of Hesperomis are given below from the type specimens. 



Measurements of Tarso-metatarsus. {Hesperomis regalis, No. 1200.) 



Left. Eight. 



Length to end of outer articulation, 136.0 mm 136.0 m 



Length to end of median articulation, 131.0 131.0 



Length to end of inner articulation, 116.0 116.0 



Antero-posterior diameter of proximal end, 21.0 21.0 



Transverse diameter of proximal end, 34.0 34.0 



Antero-posterior diameter of inner metatarsal, at the middle, 16.5 16.5 



Antero-posterior diameter of outer metatarsal, at the middle, 22.0 22.0 



Transverse diameter of shaft, at the middle, 14.0 14.0 



Transverse diameter of outer distal articulation, 15.0 15.0 



Vertical diameters of outer distal articulation, 12-20.0 12-20.0 



Transverse diameter of median distal articulation, 8.0 8.0 



Vertical diameter of median distal articulation, 15.0 14.5 



Transverse diameter of inner distal articulation, 9.0 9.0 



Vertical diameters of inner distal articulation, 12.5-14.0 12.5-14.0 



Measurements. (No. 1206.) 



Left. 



Length to end of outer articulation, 132. 11 



Length to end of median articulation, 128.0 



Length to end of inner articulation, 117.0 



Antero-posterior diameter of proximal end, 21.0 



Transverse diameter of proximal end, 32.0 



Antero-posterior diameter of inner metatarsal, at the middle, 18.0 



Antero-posterior diameter of outer metatarsal, at the middle, 22.0 



Transverse diameter of shaft, at the middle, . 13.5 



Transverse diameter of outer distal articulation, 15.0 



Vertical diameters of outer distal articulation, 15-12-19.0 



Transverse diameter of median distal articulation, 8.0 



Vertical diameter of median distal articulation, 15.0 



Transverse diameter of inner distal articulation, 9.0 



Vertical diameters of inner distal articulation, 12.5-14.0 



13 



