10 



The epiphyses of the ischia are thick and are co-ossified with each other, forming a 

 Y-shaped mass, the narrow stem of which fills the symphysis ischiopubicus. 



Menodus americanus, Leidy. 



Khinoceros americanus, Leidy, Proceeds. Acad. Philadel., 1852, p. 2 ; Anc. Fauna of Nebraska, 72, pi. xvii., figs. 

 3-4 ; Brontoiherium ingens, Marsh, Amer. Jour. Sci. and Arts, 1874, p. 85 ; Menodus ingens, Cope, Amer. Naturalist, 

 1S87, p. 1063. 



This species is represented by a horn of the left side, which has the following dimen- 

 sions : — 



Mm. 



Length from uasal meatus 210 



( Anteroposterior 110 



Diameters at base-^ 



(. Transverse 100 



A fragment of maxillary bone supports the last three premolars. They measure 113 

 mm. Transverse diameter of p. m. i. about 62 mm. (external wall lost). 



Menodus proutii, 0. N. & E. 



Scott and Osboru, Bull. Mus. Com. Zoology, xii., 5, p. 163 ; Palxolherium (?) proutii, Owen, Norwood and Evans > 

 Proceeds. Acad. Philadel., 185S, p. 66 ; Leidy, c. c, 122 ; Tilanotherium proutii. Leidy, The Ancient Fauna of 

 Nebraska, 1S53, p. 72. 



Horns of two individuals of this species were obtained by Mr. Weston. The dimen- 

 sions of the largest of these are as follows : — 



Mm. 



Length from nasal meatus 245 



( Anteroposterior ...,,, 135 



Diameters at base < 



( Transverse 70 



The lateral borders of the nasal bones flare upwards, and do uot present an inferior 

 longitudinal ridge as in M. angustigenis and M. selwynianus. 



Numerous parts of the skeleton of Menodontes are included in the collection, and I 

 have endeavored to collate them with the horns and nasal bones. Tibia; and astragali 

 are most numerous, and furnish a starting-point, especially as they may be compared 

 with the corresponding parts of the Symborodons from Colorado in my private collection. 

 Four species are represented by these bones in the Cypress Hills collection. 



Three species are represented by astragali, which differ chiefly in size. Three 

 species are also represented by calcanea, one of which has no corresponding astragalus. 

 The same three calcanea have three corresponding tibite. Two species are represented by 

 femora and two by humeri. 



I observe a series in the tibiae. Two are more robust than the third, and are of sub- 

 equal dimensions. Both have an impressed, longitudinal, groove-like fossa on the inner 

 side of the anterior angle below the crest. They differ in three respects. In one there is 

 no popliteal callus ; the insertional face of the crest is convex, and the inner anterior dis- 

 tal angle is less produced. The calcaneum is smaller. In the second there is a popliteal 

 callus, the insertional face of the spine is concave, and the distal inner anterior angle is 

 more produced In the third type there is no incised fossa of the shaft, and the general 

 form is more slender. The corresponding astragalus and calcaneum are a good deal 



