PROFESSOR OWEN ON THE GENUS DINORNIS. 13 



side which is thicker than on the outer side. The hinder and under part of the distal 

 articular surface is convex from behind forwards, sHghtly concave from side to side, in- 

 creasing in breadth as it extends forwards, and bounded laterally by two prominent 

 ridges : the division of this surface into condyles is limited to its fore part, where they 

 project forwards, are of small size, and are divided by a very wide concave interspace, 

 immediately above which is the bony canal for the extensor tendons. The distal end of 

 the tibia is expanded chiefly at its inner side, towards which it seems to be slightly bent. 

 The tarso-metatarse (PI. II. fig. 5) a little exceeds the femur in length : its proximal 

 condyloid cavities are small and widely separated by a large intercondyloid prominence, 

 and a non-articular tract behind extended upon a calcaneal process : the entocondyloid 

 cavity is as usual the deepest. The calcaneal process is simple, imperforate, and sub- 

 sides eight lines below its upper end upon the back part of the mesometatarse. The 

 concavity on the inner side of the calcaneal process is bounded internally by a ridge 

 continued from a tuberosity behind the entocondyloid cavity about two-thirds down the 

 shaft, below which is the well-marked oval depression for the back-toe (i). A small 

 foramen, indicating the interosseous space between the inner and middle metatarsals, 

 opens into the upper part of the concavity below and at the inner side of the cal- 

 caneal process. On the outer side of that process, but at a lower level, is a similar 

 remnant of the primitive space between the middle and external metatarsals : both these 

 foramina unite as usual into a single median foramen at the fore part of the proximal 

 end of the bone. A deep and wide concavity occupies the upper half of the fore part 

 of the tarso-metatarse : it is gradually filled up by the advance forwards of the middle 

 metatarsal element, which is placed as usual rather obliquely between the outer and 

 inner elements. A slight groove between the distal portion of the middle metatarsal 

 and the outer one, leads to the canal for the transmission of the adductor tendon of the 

 fourth toe. The outer and inner trochlese are nearly of equal extent, the outer one being 

 a little longer or lower : the middle trochlea is the longest as well as largest : it does not 

 advance so far forwards as in the Aptornis : each condyle is slightly grooved. 



Remains of the Apteryx. 



In the fluviatile deposits and in the cavern at the base of Tongariro, in the North 

 Island of New Zealand, bones of the Apteryx have been discovered so associated with 

 those of Dinornis, Palapteryx, Aptornis and Notornis, as to lead to the conclusion that 

 they had been buried at the same period and were of equal antiquity. Most of these 

 remains, of which a femur {fig. 6), and a tarso-metatarse (figs. 7 & 8) are figured in 

 PI. II., agree in size and other characters with the corresponding parts of the existing 

 species {Apteryx australis) : but amongst the specimens transmitted by Governor Grey 

 from the cavern at Tongariro there is a femur, which agrees in size with that of the 

 smaller species of Apteryx figured and described by my friend Mr. Gould under the 



name oi Apteryx Oivenii'. 



' Zool. Trans, vol. iii. p. 379. pi- 57. 



