164 Dii. JULIUS VON HAAST ON A NEW 



marked, as it is also in Aptenjx ; but here, too, at the very extremity, and passmg 

 through the anterior edge only, another small perforation exists not to be found in 

 Apteryx, of which I have examined a number of skeletons. The central condyle is the 

 most prominent, standing well in advance of the others, of which the inner condyle is 

 the least produced, thus, in this respect, again closely agreeing with Apteryx. The 

 trochlear groove on the middle condyle is, however, not so deeply excavated as in 

 Apteryx. 



The upper portion of the entogastrocnemial surface, scarcely indicated in Apteryx, is 

 well marked in Megalapteryx, reaching to the inner edge of the mesometatarsal near 

 the middle of the shalt on its posterior side. It then turns again towards the inner 

 edge, forming a rough well-excavated tract of an oval form, and about three fourths of 

 an inch long, for the attachment of the hallux. This tract closely resembles that of 

 Apteryx. Below it the ridge becomes much narrower, running down to within a 

 quarter of an inch to the posterior end of the articular surface on the entotrochlea. 



From the well-defined, rough, flat surface of the ectometatarsal tuberosity, which at 

 its proximal end is well defined by a deep, horizontal, and narrow incision for the 

 insertion of the gastrocnemial muscle, a rough linear tract runs down on the outer 

 edge, near the posterior side, to join the ectogastrocnemial surface, which is well defined 

 and resembles more nearly that possessed by the Dinornithidse. In Apteryx it exhibits 

 only a narrow linear surface all the way. Of course, a powerful bird like Megalapteryx 

 ought in this respect to show more resemblance to the Dinornithidse than to the recent 

 small bird. 



The interspace between the ecto- and mesotrochlese is larger than between the ento- 

 and mesotrochlege, in this respect also agreeing with Apteryx ; but as the fore parts of 

 all three trochleas are broader than the hind part, the two interspaces are narrower near 

 the fore part of the trochlese than in the middle. In Apteryx this feature is just 

 indicated, but in most of the DinornithidsB it is well marked. 



Another difference between Apteryx and Megalapteryx is exhibited in the length of 

 the ento- and ectotrochleae. In Apteryx the ecto- stands in advance of the ento- 

 trochlea ; moreover, owing to the osseous bridge below the small perforation, the upper 

 edge of the interspace between the ecto- and mesotrochleae is in advance of the same 

 edge between the ento- and mesotrochlese. In Megalapteryx, notwithstanding the 

 existing small perforation, the opposite features are observable, thus agreeing more 

 with the Dinornithidae. 



Tibia. (Plate XXX. figs. 3, 4.) 



Though this bone in many of its characteristic features resembles that of Apteryx, 

 there is ample evidence that it has others in common with the smaller Dinornithidae, 

 wliicn may, however, be easily accounted for by its larger size. However, like the 



