30 Captain F. W. Hutton on tlie Geographical 



to represent the extinct race of moas. The relations between 

 the second family, or the Stmthiones proper, are very compli- 

 cated ; but Dinornis, which alone concerns us here, appears 

 to be intermediate between the rheas of South America and 

 the emus and cassowaries of Australia and the adjacent islands. 

 It approaches the rhea in the structure of its egg-shell, and in 

 having only three pairs of sternal ribs ; while the emu, the 

 cassowary, and also the kiwi have four, and the ostrich five 

 pairs. In the structure of its feathers and in the shape of its 

 pelvis and skull the moa approaches the emu. The Stru- 

 thious birds exhibit a type of structure intermediate in many 

 respects between the Carinate birds and the extinct Dinosau- 

 rians ; and this leads naturalists to suppose that they are but 

 the remnant of a race that once spread over the whole earth. 

 About twelve species are known outside New 'Zealand} while 

 here, besides our four species of Apteryx, Professor Owen has 

 determined fourteen species of Dinornis , three of Aptornis^ 

 and one of Cnemiorms, thus making a total of twenty-two 

 species of Struthious birds, belonging to four difterent genera, 

 living in New Zealand only a few hundred years ago — that is 

 to say, nearly twice as many as are found in all other parts of 

 the world put together. 



Probably, however, some of Professor Owen's species of 

 Dinornis are but the young of others ; and it seems to me very 

 doubtful whether ^pfo?'n?6' and Cnemiorjizs should be regarded 

 as struthious birds at all. It is evident that these two genera 

 are closely related ; and if the wing-bones placed upon Cnemi- 

 ornis calcib^ans really belong to the legs of the same bird, we 

 must suppose that the sternum had a keel sufficiently developed 

 to support muscles of a size proportionate to the wings ; for 

 although we can understand how the kakapo {Stringops) ^hoiong- 

 ing to an order of deeply keeled birds, may have lost, by dis- 

 use of the pectoral muscles, the keel on its sternum, we cannot 

 possibly explain how a struthious bird could have had large 

 wing-bones developed unless it had also sufficiently powerful 

 muscles to use them. I also observe that Aptornis defossor 

 now wears a skull similar to that of the late Dinornis casua- 

 rinus^ which skull Mr. W. K. Parker says undoubtedly 

 belonged originally to a Notomis. But, omitting these two 

 genera and making a due allowance for doubtful species of 

 Dinornis, the great number of species living on so small an 

 island is very remarkable when contrasted with other parts of 

 the world. The continent of Africa, including Arabia, con- 

 tains but one (or, according to some naturalists, two) species of 

 ostrich. South America, from Patagonia to Peru, has but 

 three species of rhea, each inhabiting a separate district. 



I 



