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X. On DiNORNis (Part VI.) : containing a Description of the Bones of the Leg of Dinornis 



(Palapteryx) struthioides and of Dinornis gracilis, Owen. 



By Professor Owen, F.R.S., V.P.Z.S., Sfc. 



Read November 14, 1854. 



In my memoir of 1843', I described two femora of birds from tertiary deposits in 

 New Zealand, agreeing in size with that bone in the Ostrich, and referred them to 

 a species called Dinornis struthioides ; one of these specimens however consisted only 

 of the shaft; the other and more perfect specimen, figured in pi. 21. fig. 3, was 

 mutilated at both its extremities. I have since received, through the kindness of the 

 Rev. Mr. Colenso, M.A.^ and the Rev. William Cotton, M.A., three entire specimens 

 of femora, ranging between 11 and 12 inches in length, and the shaft of a fourth femur 

 of the Din. struthioides, confirming very satisfactorily that species, and completing our 

 knowledge of the anatomical characters of the bone. 



The head (PI. XLI. fig. 2) is rather more than a hemisphere, more prominent 

 than in the Ostrich, and with a smaller proportion cut off", as it were, from the upper 

 and outer part, and roughened for the attachment of the strong ' ligamentum rotundum.' 

 From the upper part of the base of the head, an almost flat, slightly concave, surface 

 ascends, expanding, as it rises, to the broad semicircular ridge which crowns the great 

 trochanter. In the Ostrich that process does not rise above the level of the head of 

 the bone. In the Din. struthioides the upper trochanterian platform is broader pro- 

 portionally than in the Din. casuarinus^. The anterior surface of the trochanter is 

 also extensive through the continuation outwards of the great process : it is slightly 

 concave, sculptured by muscular impressions with intervening ridges, and by a defined 

 oval rough tract between the head and the base of the trochanter. The outer convex 

 expanded surface of the trochanter is more strongly marked by the insertions of 

 powerful tendons, surrounding an irregular smooth tract near the centre of the surface. 

 The back part of the upper end of the femur in two of the specimens presents two or 

 three small holes leading into the superficial cancelli, by which it is possible a little 

 air may have been admitted to these cavities ; but this is a very feeble representation 

 of the wide orifice and canal at the same part of the Ostrich's femur which conducts 

 directly to the large air-cavity in the body of that bone. 



' Zool. Trans, vol. iii. pp. 247. 249, pi. 21 . fig. 3. 



■ The specimen contributed by this gentleman is cited in the table of admeasurements, Zool. Trans, vol. iii. 

 p. 329. 



^ Ibid. pi. 46. fig. 2. 

 VOL. IV. PART IV. Y 



