84 The Moas 



skeletons were found on the surface and so nearly in the positions in which they 

 died that the pebbles that had been taken into the gizzards were located and 

 collected. The causes which led to these mortalities are, and of course must 

 remain, unknown, /but it has been conjectured that glacial agencies may have 

 had something to do with it, or possibly those found in the cul-de-sac were driven 

 in by fire and cut off from escape by the water and the rocky ledge. 



The Moas were flightless birds, so distinctly so, indeed, that in most cases 

 every bone of the wing had disappeared. Even the coracoid and scapula are 

 aborted or absent, and the breast-bone, which in shape may be broad and short 

 or long and narrow, is without trace of a keel, and its grooves for the reception of 

 the coracoid are either reduced to small facets or have totally disappeared. Coin- 

 cident with the loss of the power of flight, which was doubtless brought about by 

 the absence of predatory land animals which made the frequent use of the wings 

 unnecessary, the hind limbs were greatly developed and made massive, though 

 not quite to the extent found in the Elephant-birds of Madagascar. The tibia, 

 which in the different species varies in length from about nine and one-half to 

 some thirty-nine inches, is chiefly remarkable for the presence of a bony bridge 

 at the lower end in front, which distinguishes the Moas from all living Ratites. 

 There were three toes directed forwards and in most cases one directed back- 

 wards. The number of vertebras is absolutely known in only one species (Anom- 

 alopteryx parva), there being in this twenty-one in the neck, and six free dorsals. 

 The skull, which, however, differs considerably in the several genera, was gen- 

 erally broad and low, with a wide U-shaped or V-shaped and somewhat de- 

 flected beak. The feathers have a distinct and large aftershaft, as in the Casso- 

 waries, and the webs are soft and dissociated. From the stoutness of the bill 

 it is inferred that they subsisted largely on vegetation, such as succulent stems, 

 seeds, and berries, with doubtless an occasional insect or reptile. 



The Moas appear to find their nearest relatives among the Kiwis, and it has 

 been assumed that like them the females exceeded the males in size, but recent 

 studies indicate that this was probably not the case. They differ from them, 

 however, in the short beak, and feathers with aftershafts, as well as in certain 

 anatomical features. They were most abundant on the South Island, but were 

 present on the North Island, and a single rather doubtful species, based on one 

 bone, has been reported from Australia. 



