Hutton. — On the Dimensions of Dinornis Bones. 277 



to the publication of the measurements on which these sub-species and sexes 

 have been founded. 



In order that others may be able to form an idea of the nature and 

 complicated character of the variations in these bones I have added a table 

 (Table B) showing the dimensions of all the bones of D. casuarinus from the 



Hamilton 



I have selected D. casuarinus because we 



know that the metatarsi and tibiae belong to the same species, although the 

 femora may be incorrectly associated with them. If I had taken D. crassus 

 or D. elephantopus as an illustration the gradations would have appeared more 

 minute and far more intricate, as my material is so much greater. 



Among the metatarsi of D. crassus and D. eleplmntopus there are certainly 

 two very different forms, in one of which the trochlea? are widely diverging, 

 and in the other more longitudinal ; and I tried to arrange them in two series 

 according to the relative breadths of the distal extremity and the middle of 

 the shaft, but the result was only to convince me more than ever of the 

 extraordinary variation in these species of Dinornis. and I abandoned the 

 attempt, as by adhering to it I should have had to depart so widely from the 

 dimensions given by Professor Owen that my principal object in compiling 

 Table A, viz., to show that the "species D. crassus and D. elephantopus, as at 

 present characterized, cannot be maintained — would have been lost. I also 



attempted to separate the tibiae by their greater or less curvature, but this 

 also led to the same results — a gradual passage from one to the other. Indeed 

 the variation is so great that with over a hundred metatarsi of D. crassus and 

 D. elephantopus lying before me, I have had very great difficulty in selecting 

 a right and left sufficiently alike to make a presentable match. 



Still, notwithstanding all that I have said, I am convinced that it will be 

 necessary to retain the names both of crassus and elephantopus to mark both 

 ends of the series as characterized by the proportions of the metatarsus, the 

 length of which in D. crassus is more than four times the breadth of the 

 middle of the shaft, while the length is less than four times the breadth in 

 D. elephantopus and D. gravis. But I think that we must wait patiently for 

 more information before we assign tibiae and femora to them. 



It may . be that when these bones from Hamilton are studied by a 

 competent anatomist he may be able to point out constant marked anatomical 

 characters which would enable him to refer them with certainty to Professor 

 Owen's species, and if such should be the case no one would be more pleased 

 than I, for I think no one has been more puzzled with them ; but I confess to 

 having great doubts about it, especially as the very highest authority 

 Professor Owen himself— has said that he is ready and willing to yield up any 

 of his species should intermediate sizes of femur, tibia, and metatarsus, without 

 distinct and well-marked modifications of form or proportions be found (Trans. 

 Zool. Soc. ? VIII, p. 361), 



