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X. On DiNORNis (Part XVIII.): containing a Description of the Pelvis and Bones of 

 the Leg 0/ Dinomis gravis. By Professor Owen, F.E.S., F.Z.S., &c. 



Bead May 7th, 1872. 



[Plates LVIII. to LXI.] 



It is with feelings akin to compunction that I come again before the Society with 

 claims to place the record of a fifteenth species of Binornis in a volume of its Trans- 

 actions. I have hesitated for some years in completing this step, tentatively ventured 

 in 1869'. But I have no alternative; for I do not see my way, on present experience 

 of the value of characters from leg-bones, to attach thereto other interpretation of 

 those about to be described than that which has led me, in the British-Museum Lists, 

 to refer them to a Binornis gravis. 



The fourteen extinct species of terrestrial or wingless birds proposed in preceding 

 Memoirs being characterized by bones only, and chiefly, or mostly, by those of the hind 

 limbs, might well be deemed by ornithologists to require subsequent confirmation 

 before they received general acceptance. Eemarks by some esteemed friends, eminent 

 in that branch of natural history, significant of their reticence or expectant attitude, 

 have not surprised mc, and ought not. 



I look forward with equal interest, at least, to the result of further acquisitions of 

 these remarkable and unexpected evidences of avian life in the old times of New Zea- 

 land ; and I believe myself ready and willing to yield up any of my species, should 

 intermediate sizes of femur, tibia, and metatarsus, without distinct and well-marked 

 modifications of form or proportion, prove the Binornis struthioides, e. g., to be an 

 immature Binornis ingens, or this to show merely a stage of growth of Binornis 

 giganteus. 



I can only say that I prepared myself to grapple with the problem of these bones by 

 a comparison of all accessible materials showing age-characters in the femur, tibia, and 

 metatarsus of the known existing struthious birds, and have noted^ and represented" 

 some of the characters by which the leg-bones, say of an immature Ostrich, might be 

 detected and discriminated from bones of the same size of the Emu, Ehea, or 

 Cassowary. 



It was not until I had satisfied myself that characters as distinctive as those observable 

 in the leg-bones of the existing large species of Cursores or Struthionidse were present 



' Trans. Zool. Soo. vol. vii. part 2, p. 141. ' lb. vol. iii. p. 243 (1843). 



2 lb. vol. iii. pi. 28. figs. 1 & 2. 



VOL. viiL — PAET VI. May, 1873. 3 r 



