338 C. W. Andreas — On Diaphorapteryx. 



The most interesting of the extinct flightless birds discovered by 

 Forbes is Diaphorapteryx Hawkinsi, a nearly complete skeleton of 

 which is figured on Plate XII. This remarkable bird is a rail 

 closely allied to Oeydromus, of wliich several species, all incapable of 

 flight, inhabit New Zealand. It is also very similar to Aphanapteryx 

 Broecki, of Mauritius — indeed, Forbes has referred it to the same 

 genus, although for a time he placed it in a separate one, Diaphor- 

 apteryx. In a detailed account of the osteology of this bird by the 

 present writer, 1 it was shown that it differed from Aphanapteryx in 

 many points, particularly in the form of its metatarsus, and the name 

 Diaphorapteryx was therefore adopted ; in a recent memoir by Prof. 

 A. Milne Edwards 2 on some of the Chatham Island birds the same 

 conclusion is arrived at. 



The skeleton here figured consists almost entirely of bones be- 

 longing to one individual, but the deficiencies have been made good 

 from the immense collection of bird-remains lately obtained from the 

 Chatham Islands by the Hon. Walter Rothschild, in whose museum 

 at Tring the present specimen is pi'eserved. The skull is chiefly 

 remarkable on account of its relatively large size and long curved 

 beak. In the vertebral column as mounted there are twenty-three 

 free vertebrae, thirteen of which are cervioals, two cervico-dorsals 

 (with short free ribs), and eight dorsals ; the number of cervicals is 

 no doubt correct, but it is possible that a dorsal too many may have 

 been introduced. The pelvis, as in most flightless birds, is relatively 

 large ; it is very similar to that of Oeydromus. The pelvis figured by 

 Milne Edwards in the memoir mentioned above (pi. xi, fig. 7 ; pi. xii, 

 figs. 1 and 2) is certainly not that of Diaphorapteryx, or, indeed, of 

 any rail, but seems rather to belong to some anserine bird. The 

 hind limbs are long and powerful, well adapted for running, and 

 also, judging from the stoutness of the metatarsus, for scratching in 

 the earth. In Aptornis 3 the metatarsus is even more massive, so that 

 in this respect, as in several others, Diaphorapteryx comes midway 

 between that bird and the living Ocydromine rails. The sternum is 

 very like that of Oeydromus, but the keel is still more reduced. The 

 coracoids are very small, and appear to have made an obtuse angle 

 with the scapulae, as is usually the case in birds incapable of flight. 

 The wings are very small in proportion to the bulk of the bird, the 

 metacarpus especially being extremely short. 



I am indebted to the Hon. Walter Rothschild for permission to 

 figure this specimen, and also to my colleague, Mr. A. Gepp, for the 

 photograph reproduced. 



1 "On the Extinct Birds of the Chatham Islands." Pt. I. The Osteology of 

 Diaphorapteryx Hawkinsi. — Novitates Zoologies, vol. iii (1896), p. 73, pi. iii. 



2 " Sur les Kessemblances qui existent entre la Faune des lies Mascareignes et 

 celle de certaines lies de l'Ocean Pacifique Austral": Ann. Sci. Nat. (Zoologie), 

 ser. viii, vol. ii, p. 117, pis. xi-xv. 



3 A skeleton of Aptorms defossor was figured about one-sixth natural size on 

 Plate X of the present volume. 





