MUSEUM OF COMPAEATIVE ZOOLOGY, 163 



represented by M. tichoceras, and characterizes M. Proutii and M. altirostris. 

 The third, with short obtuse nasals and long horns, is represented by M. doli- 

 choceras, M. acer, and M. platyceras. 



There are doubtless other species of Menodus in this collection, but the fore- 

 going are the only fully defined types. The lower jaw with three lower incisors 

 probably belongs to a new species. There is also a pair of diminutive horns, 

 resembling those of S. heloceras, Cope. Another pair of horns presents a smaU 

 knob upon the antero-interior surface, about half-way to the tip, which gives 

 the horn quite a different aspect from those above described. 



Restoration op M. Proutii. 



The accompanying restoration of Menodus (see Plate II.) is from materials 

 in this collection, in the E. M. Museum of Princeton, and in the collections 

 of Professor Cope, as follows : Mus. Comp. Zool., the fore and hind limbs 

 and fore feet. E. M. Museum, the pelvis, hind feet, anterior dorsal verte- 

 brae, the cervical vertebrae, the anterior ribs, and skull. The scapula and 

 outlines of the processes of the cervical vertebrae and spines of the first and 

 second dorsal vertebrae are from the Cope collection. The outlines of the pha- 

 langes of the fore foot are from specimens in the Cambridge collection, and 

 from Professor Marsh's drawings. AU the structures which are wholly or in 

 part conjectural, such as the sternum, the outline of the scapula, the lumbar 

 vertebrae, and sacrum, are drawn in plain or dotted lines without shading. On 

 the other hand, several of the ribs which are known from the Princeton col- 

 lection are not shaded, for the sake of uniformity. Several of the posterior 

 dorsal vertebral centra are shaded for the relief eflFect. The proportions of the 

 neck, back, and pelvis, with those of the skull, are known from the fact that 

 these parts in the Princeton collection belong together, i. e. to one individual. 

 The larger bones of the fore and hind limbs are also, for the most part 

 from a single individual ; and a number of vertebrae found with the head 

 of a radius of another individual enable us to determine the proportion be- 

 tween the fore limb and the centra of the dorsal vertebrae. The size of the 

 scapula, which belonged to an isolated series, was fixed by the proportions 

 which obtain between this bone and the humerus in the Proboscidia, Rhino- 

 ceridce, and Dinocerata ; viz. that the scapula varies from ^ to f the length of 

 the humerus. We have given it |- the humerus length. 



The animal is placed in an erect standing position, the right leg being drawn 

 slightly back. The fore limb is placed nearly at the maximum of extension ; 

 the angle of this limb, as indicated by the articular facets of the head and 

 trochlea of the humerus, being intermediate between that of the elephant and 

 rhinoceros. It was capable of being flexed to a much greater degree than 

 is here represented, so as to bring the animal nearer the ground. 



The skull and neck, to which the trunk and limbs are proportional, proba- 

 bly belong to M. Proutii, a species of about the medium size attained by these 

 animals ; for, judging by the measurements of the skuUs which are known. 



