BY C. W. DE VIS. 245 



indeed, exceeds in this respect that of platyrhinus ; it is 124*5 mm. 

 long, and would be of exactly the same length as in platyrhinus 

 but for an elongation of the ectotuberosity ; both the breadth of 

 the proximal end and the length of the condyles are as they are in 

 the living species, the teretotriceps ridge is of the same extent and 

 form. The head is a little and the great tuberosity much narrower, 

 the latter is altogether different in shape from that of mitchelli and 

 platyrhinus both, it rises high above the level of the head as an 

 obtusely pointed backwardly inclined peak separated from the 

 neck by a low transverse ridge. The facet on its posterior aspect 

 is larger than in platyrhinus but less defined, and in the middle 

 of its length it is more deeply impressed. The lesser tuberosity 

 is, on the other hand, much less elevated, and is more distinctly 

 connected with the greater by the tumid edge of the anterior 

 surface of the shaft. On this aspect the greater tuberosity is 

 much less convex than in other species. The pectoral ridge is 

 not quite so distinctly continuous with the greater tuberosity as 

 in P. mitchelli, but it is higher and at its distal end forms a larger 

 and better denned tubercle. As in P. mitchelli the deltoid ridge 

 terminates in a retroflected angle, but one of greater expansion. The 

 prominence on the long oblique edge joining the ends of the two 

 ridges is much larger and sharper, and from it a thread-like ridge, 

 a rudimentary predeltoid, runs proximad for a few millimetres. 

 The breadth of the shaft at its proximal third is 22J mm. ; 

 at this point it is but 12*8 in antero-posterior thickness against 

 14*5 in platyrhinus and 17*5 in mitchelli. The length of the shaft 

 from the convex edge between the tuberosities to the end of the 

 pectoral ridge is 61*5 mm., in platyrhinus it is 59, and in mitchelli 

 55. As in mitchelli, the posterior limit of the head descends low 

 and angularly upon the shaft, overhanging it more than in the 

 stouter bone. The ridge for the humeral head of the triceps is 

 wanting, or it may be represented by a very small prominence 

 near the edge of the shaft. The anconal and coronal pits of the 

 distal end have a large foramen in common. The condyles are 

 narrow antero-posteriorly, the intercondylar rotular surface 

 remarkably so. The outer condyle is almost perfectly globose. 



