maksh.] CLAOSAUEUS. 223 



margin, above the articulation for the coraeoid, is a strong protuber- 

 ance, with a well-defined facet, adapted to the support of the clavicle, 

 if such a bone were present. The coraeoid is very small, and is per- 

 forated by a large foramen. The two peculiar bones now generally 

 regarded as belonging to the sternum were separate, as shown in PI. 

 LXXY. fig. 4. 



The humerus is comparatively short, and has a prominent radial 

 crest. The radius and ulna are inuch elongated, the latter being longer 

 than the humerus, and the radius about the same length. The ulna 

 has a prominent olecranon process, and is a stouter bone than the 

 radius. The carpal bones were quite short, and appear to have been 

 only imperfectly ossified. The fore foot, or manus, was very long, and 

 contained three functional digits only. The first digit was rudimentary, 

 the second and third were nearly equal in length, the fourth was shorter 

 and less developed, and the fifth entirely wanting, as shown in PI. 

 LXXIII, fig. 1. 



In the functional digits (n, in, iv) the phalanges are elongate, thus 

 materially lengthening the fore foot. The terminal phalanges of these 

 digits are broad and fiat, showing that they were covered with hoofs, 

 and not with claws. The limb as a whole was thus adapted to loco- 



m 



P ; ' 



~~~' is 



Fig. 55. — nium of Claosourus aoi!i.s ilarsh ; seen from the left. One-sixth natural size 

 a, acetabular border: *'.«. face for ischium; p, face for pubis. 



motion or support, and not at all for prehension, although this might 

 have been expected from its small size and position. 



The elongation of the forearm and manus is a peculiar feature, espe- 

 cially when taken in connection with the ungulate phalanges. It may, 

 perhaps, be explained by supposing that the animal gradually assumed 

 a more erect position until it became essentially a biped, while the fore 

 limbs retained in a measure their primitive function, and did not become 

 prehensile as in some allied forms. 



The pelvis is shown in PI. LXXIII, figs. 2 and 3, and has been 

 fully described by the writer. Its most notable features are seen in 

 the pubis and ischium, the former having a very large expanded pre- 

 pubis, with the postpubis rudimentary, while the shaft of the ischium 

 is greatly elongated. The ilium of the type species is shown in fig. 55. 



The femur is long, and the shaft nearly straight. The great trochanter 

 is well developed, while the third trochanter is large and near the middle 

 of the shaft, as shown in PI. LXXIII, fig. 2. The external condyle of 



