189].] MR. R. LYDEKKER ON A NEW MOA. 481 



bone are so abraded that nothing can be gathered as to the contour 

 of the trochlese. Approximately, it has a length of 8'5 inches and 

 a width at the middle of the shaft of 2*1 inches, while it measures 

 about 5 inches across the distal trochlese. In the tarso-metatarsus 

 of Pachyornis elephantopus the corresponding dimensions are O'^, 

 2'55, and 5'5 inches. The present specimen is therefore of a 

 somewhat more slender type than the latter, but when complete 

 appears to have had the distal trochleae somewhat more expanded in 

 comparison with the shaft and proximal extremity. There does not 

 appear^ however, to be any well-marked character by which it can be 

 geuerically separated from Pachyornis. Compared with the typical 

 species of that genus^ somewhat more important differences are shown 

 by the femur, of which the ventral aspect is represented in Plate 

 XXXVIII. fig. 1. It may be observed that the femora of Dinornis 

 maximus and Pachyornis elephantopus are contrasted in the Cat. 

 Foss. Birds Brit. Mus. p. 223, fig. 57^; the former being charac- 

 terized by its great length and slenderness and the small size of the 

 popliteal depression, while the latter is distinguished by its shortness 

 and stoutness and the large size of its popliteal depression, which 

 commuuicates with the inner surface of the shaft by a more distinct 

 channel, as well as by other features noticed in the work cited. Now 

 the femur of the present bird, while agreeing with that of Pachyornis 

 elephantopus in the contour and dimensions of the popliteal depression 

 and in the form of the linea aspera, somewhat approximates in its 

 general proportions to the corresponding bone of Dinornis, as is 

 shown by the following dimensions : — 





Dinornis 



New 



Pachyornis 





maximus. 



species. 



elephantopus. 



Total length of femur . . 



. . .. 15-6 



10-6 



12-5 in. 



Distal width of femur . . 



.. .. 6-9 



4-9 



6*5 in. 



The present type of femur is in fact more like the corresponding 

 bone of Anomalopteryx and Emeus. On the other hand, the femur 

 which I have provisionally referred ^ to Pachyornis immanis has pro- 

 portions much more like those of the present specimen, having a 

 length of 14'4 and a distal width of 6*1 inches. This type of femur 

 seems, indeed, to make it impossible to separate generically the 

 present form from Pachyornis, to which genus I propose to refer it 

 provisionally under the name P. rothschildi. 



In the work cited (p. 318) I have stated that the genus Pachyornis 

 approaches Anomalopteryx, so far as cranial characters are concerned, 

 much more nearly than it does to Emeus, and the present species 

 serves to approximate Pachyornis in regard to slenderness of limb to 

 the same genus, although the inflection of the lower end of the tibio- 

 tarsus remains as well marked as in the type species. In the * Cata- 

 logue' I had very great hesitation in referring the limb-bones 

 mentioned under the name of Anomalopteryx (?) geranoides to the 



^ In the description of this figure tlie scale is given as \ instead of |, 

 * Oi>. ci!;. p. 344. 



33* 



