( 188 ). 



ON A COMPLETE SKELETON OF MEGALAPTERYX 

 TENUIFES Lydekker IN THE TRING MUSEUM. 



Bv CIIAKLES W. .USfDREWS, B.Sc, F.G.S. 



(Plate VI.) 



THE confusion that has arisen in the nomenclature of the Dinomithidae in 

 consequence of the founding of new species on isolated bones, or, what is worse, 

 on sets of bones conjecturally referred to the same species, has often been commented 

 upon, and some attempts have been made to remedy it. The difficulties are, however, 

 so great that the confusion is probably to a large extent ine.xtricable, and the whole 

 question is rendered more difficult by the way iu which many of the nominal species 

 pass into one another by almost imperceptible gradations. Nevertheless, when more 

 associated sets of limb-bones, or, better still, complete skeletons, have been described 

 and measured, it will become possible to determine to a large extent how many good 

 species there really are, although there will no doubt always be considerable difference 

 of opinion as to the limits of some of them. 



In the case of the almost perfect skeleton which, through the kind permission of 

 the Hon. Walter Rothschild, I am able to describe iu the present paper, the difficulty 

 of determination is comparatively small, since it clearly belongs to the genus 

 Megalapteryx, of which only two species have hitherto been named. The first of these, 

 Megalnpteryx hectori, which is the type of the genus, was described by Von Haast in 

 the Transactions of the Zoological Society, Vol. XII. p. Ifil, on the evidence of the 

 bones of the leg. The second species, M. tenuipes, was founded by Lydekker (Cat. 

 Fosa. Birds Brit. Mus. p. 251) on a much abraded right tibia (Brit. IMus. 49990); 

 and since the tibia of the skeleton under description is identical with this bone in size 

 and structure, it must be referred to the same species. At the same time I regard 

 it as very unfortunate that so imperfect a specimen as the type tibia should have 

 received a name at all. 



The genus Megalapteryx is the least known of the numerous genera into which 

 the Dinomithidae are subdivided. As already mentioned, it was founded by Haast 

 for the reception of his new species M. hectori, and the chief character which he put 

 forward as diagnostic of it was the slenderuess of the bones of the leg, this being 

 jiarticularly marked in the case of the femur, in which the shaft is notably longer in 

 proportion to the size of the extremities than in any other member of the group. He 

 also drew attention to several other points which led him to believe that this bird was 

 nearly related to the Aplerygidae, and was, iu fact, a gigantic apteryx. This opinion 

 is rejected by later writers, and is not supported by the present specimen, which is 

 in all respects Dinomithine ; and, as Parker has pointed out, the skull in this genus 

 is very similar in many respects to that occurring in Haast's genus Meionomis 

 ( = MesojAeryx Ilutton, and Anoinaloplcryx, typical groui), Lydekker). It should, 

 however, be noted that some of the characters (e.g. the presence of a perforation at the 

 lower end of the groove between the third and fourth metatarsals) to which Haast 

 attached importance, occur in the skeleton under consideration, and appear, therefore, 

 to be constant in the genus. 



