178 DE. J. VON HAAST ON A NEW SPECIES OF DINOENIS. 



towards the ectocondylar fossa. The interspace between the two ridges is first about 

 0-25 inch wide, but it gradually increases to about 0"50 inch above the popliteal space. 

 The rough tract at the lower part of the pretrochanterian surface situated in the 

 middle between the head and the ectotrochanterian tuberosity is also well marked. 

 The rotular cavity is comparatively flatter than it is in the other small Dinornithidse, 

 and the ridge between it and the intercond}lar fossae is well defined, falling vertically 

 towards the latter, which are far more excavated than those in the other Dinornithidse. 

 The postintercondylar ridge is also sharper and more prominent in this small species. 



The entocondylar surface for the tibia appears a little flatter, and the ectocondylar 

 surface narrower than in the other Binornis species. At the same time, the space for 

 the head of the fibula is not excavated but flat, thus resembling Megalapteryx, the 

 ectocondylar ridge being also proportionally narrower and higher than in the other 

 Dinornithidse. The popliteal space closely resembles that of the larger Binornis 

 species, though, in comparison to size, it appears a little more deeply excavated. 

 Thus, notwithstanding its remarkably small size, this bone has all the most charac- 

 teristic features of the larger Dinornithidse which have been repeatedly and fully 

 described by Sir Eichard Owen in his masterly Memoirs. 



Tibia. 



Measurements. inches. 



Length 9-58 



Middle of shaft 0-75 



Proximal end of shait 2*50 



Distal end of shaft 1-48 



The tibia also has all the characteristic peculiarities of that of the larger Dinornithidse, 

 with the exception that its shaft is comparatively more slender and possesses an outward 

 curve or bend, the bird thus having been rather bow-legged. This latter character, 

 however, it had in common with Binornis ciirtus, to which it is doubtless generically 

 allied. The entocondylar surface has an oval shape, the margin along the intercondylar 

 channel being, however, less curved than the opposite outline. The ectocondylar surface 

 is rather pointed, and the ectocnemial ca^dty well excavated, so that the proximal end 

 is here rather narrow, taking its length into account. The epicnemial ridge rises con- 

 spicuously and at a steep angle above the epicnemial channel, more so than in most of 

 the Dinornithidse. The procnemial ridge is well defined and crosses the shaft, as in the 

 other Binornis species, so as to form at its termination the inner boundary of the extensor 

 groove. The suprafibular facet is divided from the fibular ridge by a smooth surface 

 of 0'85 inch in length. In some of the larger Dinornithidte this surface is scarcely 

 wider, and in Binornis maximus it has only a length of 2 inches. The broad fibular 

 ridge, divided into two portions, is 4"50 inches long. Near the lower end of the upper 



