MCEEITHEEirM. 117 



be regarded as a free sacral rather than as a caudal. The centrum is depressed, and its 

 ventral face only slightly convex from side to side, passing externally into the broad 

 transverse processes. The anterior end of the centrum is convex, and slopes somewhat 

 forwards ; the posterior end is much higher in proportion to its width : this vertebra 

 is, in fact, intermediate in form between the sacrals and caudals. These latter are not 

 known in the present specimen, but in another, much less nearly complete, column 

 several are preserved. Their centra are laterally compressed, particularly behind, so 

 that while the anterior face of the centrum is nearly circular, the posterior is a vertically 

 elongated oval. The neural arch seems to have been confined to the posterior half of 

 the centrum. There are short downwardly directed transverse processes towards the 

 anterior end. Posteriorly the ventral border bears facets for chevrons, which, in some 

 cases at least, were V-shaped. 



Fore Limb. — The scapula, the humerus, and the proximal portion of the ulna only 

 are known. No complete specimen of the scapula has yet been found. The best 

 example (from the left side) is figured in PI. XL fig. 5. The glenoid cavity {g.c.) is 

 oval in outline, and the articular surface is continued forwards on to the posterior 

 surface of the large and prominent coracoid process (c). Anteriorly this process bears 

 a rough ridge, which passes above into the coracoid border {c.h.). This border is 

 concave below, but is incomplete above ; it seems, however, to have curved forwards so 

 that the upper part of the blade was M'ide. The glenoid border {g.l.) is gently curved 

 backwards ; the suprascapular region is broken away. The spine (s.) originates 

 about 2'5 cm. from the glenoid cavity ; it forms a prominent backwardly inclined 

 flange, parallel with the glenoid border ; it cannot be seen whether or not there 

 was an acromion. The postscapular fossa is narrow but deep, and overhung by the 

 spine ; the prescapiilar fossa is wider and more open. This scapula, in the backward 

 sweep of its blade, presents some approach to the Sirenian type, and in the large 

 size of the coracoid process and the form of its coracoid border is similar to the 

 scapula of Barytherium described below. 



In the humerus (PI. XL fig. 6) the head [h.) projects strongly backwards and inwards ; 

 it is much more strongly convex from before backwards than from side to side. The 

 greater tuberosity is large and rises to about the same level as the head. Externally 

 it is flattened, internally it forms the outer border of a broad bicipital groove, the inner 

 side of which is formed by the small but still well-defined lesser tuberosity. The 

 shaft is chiefiy remarkable for its extreme lateral compression. The narrow flat anterior 

 surface is continuous above with the flattened face of the greater tuberosity ; lower 

 down it passes into the inner face of the bone, its prominent outer border forming the 

 deltoid crest {d.), from which a rounded ridge runs obliquely across the anterior face of 

 the bone to the inner end of the distal articular surface, so that the whole bone when 

 seen from the front appears to have a slight spiral twist. The inner condyle [i.e.) is very 

 large and projects below the rest of the bone ; it is not perforated by an entepicondylar 



