668 



TITANOTHERES OF ANCIENT WYOMING, DAKOTA, AND NEBRASKA 



and 70 transversely; the flattening of the body of this I 

 element is partly due to crushing. The supposed 

 third sternebra is deeper, measuring 35 millimeters 

 vertically, and shorter (ap. 95 mm.) and somewhat 

 narrower (tr. 64 mm.). The supposed fourth 

 sternebra, which was largely cartilaginous at the 

 extremities, measures 39 millimeters vertically, 70 

 anteroposteriorly, and 72 transversely. 



Scapulae. — As partly restored, the scapulae of the 

 type measure 690 millimeters vertically and 530 

 transversely; they are characterized by the narrow 

 rectangular prespinous fossa, the large, broadly 

 triangular postspinous fossa, and the rugose retro- 

 verted acrominal spine. 



Humerus. — The humerus measures 622 millimeters 

 from the head to the inner condyle. As admirably 

 shown in Plate CCV, it exhibits (1) the deep bicipital 

 groove (fig. 5), (2) the elevated platelike tuberosity 

 (fig. 4) indented on the anterior superior border 

 (fig. 5), (3) the prominent deltoid ridge terminating 

 in the characteristic prominent and somewhat up- 

 turned knob (figs. 1, 3), (4) the rugose supinator 

 ridge, (5) the very marked upward extension on the 

 shaft of the internal radial facet (fig. 1). 



Radius.— The radius (PL CCVI), measuring 495 

 millimeters, exhibits a transverse diameter of 170 

 millimeters for the humeral facets (fig. 5) and of 

 118 for the scaphoid and lunar (fig. 6). The rugose 

 insertion of the brachialis anticus muscle is placed 

 about the middle of the shaft (fig. 1). The shaft is 

 well rounded in midsection (fig. 2 a), the transverse 

 diameter being 78 mllimeters. 



Ulna.— The ulna (PI. CCVII) , having a total linear 

 measurement of 680 millimeters (olecranon to unciform 

 facet), exhibits the characteristic groove (figs. 2, 3) 

 in the top of the olecranon; a stout trihedral shaft. 



Manus. — The right and left manus are both 

 preserved; the unfortunate absence of both lunar.s 

 renders it difficult to ascertain the exact characters 

 of this important element. The total width of the 

 proximal row of carpals (fig. 1) across the facets 

 is 200 millimeters (estimated), of the distal row 

 202; the vertical depth through the anterior faces of 

 the scaphoid and magnum is 92; the length of Mtc 

 III is 210; the height from the scaphoid to the extrem- 

 ity of the median metacarpal is 322; this manus, 

 therefore, may be described as moderately broad and 

 short. (See PI. CCXXVIII.) 



The detailed structure of the carpals as figured in 

 Plates CCVIII-CCXI is important. The maximum 

 measurements of the scaphoid (PI. CCVIII, fig. 5 r) 

 are, vertical 65 millimeters, transverse (radial face) 

 73, anteroposterior 82; the magnum facet (fig. 4) 

 is exceptionally narrow (30), and the scaphoid is 

 therefore relatively narrow transversely, deep verti- 

 cally, and extended anteroposteriorly. The radial 

 facet of the missing lunar is estimated at 170 milli- 



meters, its magnum facet at 25, the unciform facet at 

 53; this bone had a relatively narrow, oblique facet 

 on the magnum and a much broader facet on the 

 unciform. The cuneiform (PI. CCIX, figs. 1-6) is 

 a smaller element, moderately deep (52 mm.) 

 vertically, with a rectangular ulnar facet (fig. 5) 

 which measures 57 millimeters transversely and 48 

 anteroposteriorly. The pisiform (PI. CCIX, figs. 

 7-12) is large, measuring 125 millimeters antero- 

 posteriorly. The trapezoid (PL CCX, figs. 1-6) 

 exhibits no evidence of a trapezium facet; it is rather 

 shallow (ap. 37 mm.) with a moderately broad 

 scaphoid facet (fig. 5 s), 53 millimeters transversely, 67 

 anteroposteriorly. The magnum (PL CCX, figs. 

 7-12) measures vertically 40 millimeters and trans- 

 versely 65 on the anterior face (fig. 7), with a broader 

 scaphoid (fig. 7 s) (35) and a narrower (20) lunar 

 facet (fig. 7 I). The unciform (PL CCXI, figs. 1-6) 

 is a very large element, its maximum breadth being 

 114 millimeters, height 58, depth of cuneiform facet 

 (ap.) 53 (fig. 1 p); superiorly (fig. 5 Z) it exhibits a 

 broad (55) lunar facet and a slightly broader cunei- 

 form facet (fig. 5 p) (60); on the lower surface (fig.6) 

 it has a narrow (12) abutment against the magnum 

 (fig. 6 m) and a broader facet for Mtc III (27) (fig. 

 6 mc III). 



The metacarpals (Pis. CCXII-CCXV) on the 

 anterior face to the distal facet measure, Mtc II, 

 220 mniimeters; Mtc III, 225; Mtc IV, 210; Mtc V, 

 180. Their characters are so admirably shown in the 

 figures that they require no further description. The 

 proximal phalanges are figured in Plate CCXVI; 

 the median and distal phalanges and sesamoids are 

 figured in Plate GCXVII. It is noteworthy that the 

 distal phalanges are of moderate size and breadth, 

 very much smaller than in the American Museum 

 skeleton referred to Brontops, somewhat broader than 

 in Menodus. 



Pelvis. — The pelvis is decidedly broad, the entire 

 width across the ilia being 1,220 millimeters (esti- 

 mated), as compared with 908, the length of the left 

 innominate bone (ilium to ischium). The pelvic 

 outlet measures 373 millimeters vertically (pubic 

 symphysis to sacrum) and 350 transversely. The 

 pubo-ischiadic symphysis measures 357 "millimeters 

 longitudinally. The extreme breadth of the iliac 

 plates is 407 millimeters. A more detailed discussion 

 of the characters of the pelvis is continued below. 



The association of the fore and hind limbs in this 

 superb specimen is especially important as giving us 

 the proportions. 



Femur.— The femur (PL CCXX) measures 820 

 millimeters and the tibia 465. The shaft of the femur 

 is somewhat crushed proximally, the great trochanter 

 extends far (395 mm.) down the outer side, the width 

 across the condyles distally is 187, the patellar trochlea 

 is distinguished by the prominence of the inner facet 



