DR. J. VON HAAST ON A NEW SPECIES OE DINORNIS. 173 



Measurements. . , 



inches. 



Breadth at temporal fossa? T63 



Breadth at mastoid process 2*43 



Breadth at supraorbital ridge 2*64 



Height of cranium between basisphenoid and trans- 

 verse occipital ridge 1-25 



Breadth of foramen magnum 0-54 



Height of foramen magnum 0*45 



The anterior border of the frontal is unfortunately broken off, so that the articulation 

 for the nasal bones is missing. Though the cranium evidently belongs to a full-grown 

 bird, the sutures are not entirely obliterated. The vertical ridge marking off the 

 anterior third of the temporal fossa?, as figured by Owen, is represented on the 

 Whangarei cranium by a linear depression which starts on the parietal with an oblique 

 direction forwards and downwards. The supraoccipital region is very broad and low, 

 with an upward and forward slope, and a well-defined vertical ridge in the centre. The 

 occipital tubercle is 0T4 inch broad and - 07 inch high, and therefore much more 

 flattened vertically than in most of the Dinornithidse. The paroccipitals are partly 

 broken away, but they appear to have been broader and less pointed than in Dinornis 

 parvus. The two precondyloid foramina on each side of the condyle are, as usual, very 

 small, but the vagal foramen on each side close to them is large. The basisphenoid 

 is also considerably destroyed, as well as the entire presphenoid, so that I am unable to 

 allude to them more fully. The mamillar tuberosities of the basisphenoid, though partly 

 broken away, seem also to have been well developed. A very characteristic feature of 

 this skull is the remarkable flatness, not only of the whole parietal, but also of the 

 posterior third of the frontal before the cranium slopes downwards. This latter feature 

 is only partly indicated in the cranium figured by Sir Richard Owen. 



The temporal fossa? are very wide and deep, and are well defined by a continuous 

 ridge dividing them from the occipital surface, so that there is no flattened tract as in 

 most of the Dinornithidse. Dinornis oweni has this character in common with Dinornis 

 parvus. The articular surface for the os tympanicum on the mastoid corresponds 

 closely to the description given by Sir Richard Owen. The whole character of the 

 cranium proves that this species, though so small, was nevertheless powerfully built 

 and capable of using its beak with remarkable force. No tympanic bones were found 

 with the cranium, but fortunately the premaxillary and greater portion of the mandible 

 are preserved. The former has the pointed form of the same bone in that subgenus of 

 the Dinornithidse to which I ventured to apply the name of Meionornis {casuarinus 

 and didiformis). It is somewhat narrower than the premaxillary in Dinornis parvus. 



The right ramus of the mandible is complete, it is rather narrow and thin in 

 comparison with the same bone in Dinornis parvus ; the symphysis is also restricted, 



