164 ME. "W. K. PAEKER OX THE STEUCTUEE AND 



of these forms if the latter bird is put at once into its own group ; its specific name may 

 stand, but I shall take the liberty, for the present at least, to speak of this huge Rail as 

 Notornis casuarinus. In the Dinomis (see the photographs mentioned above) the occi- 

 pital condyle is sessile, transversely oval, and deeply dimpled ; in the great Notornis this 

 condyle is elegantly hemispherical, strongly pedunculated, and has the dimple obsolete. 

 In the Dinornis, as in the other Ostriches, the basioccipital is deeply scooped in front of 

 the condyle below^, and then becomes very tumid ; in the Notornis there is one continuous 

 concavity along the mid line, from the condyle to the front of the basitemporals ; whilst 

 each side of the bone gives off a strong keel where it joins with the down-turned edges 

 of the exoccipitals ; thus we get the most perfect counterpart of the basioccipital region 

 of the " Delphinidse." In the Dinomis the foramen magnum is subcircular ; in the 

 large Notornis it is oblong, being very high, and having almost straight sides. The 

 exoccipitals of the Dinornis are very shallow, and help to form the tympanic cavity to a 

 small extent only ; the reverse of this is the case in the Notornis. In the Dinornis the 

 basitemporals are small and entirely lateral ; and in this photograph, in which the skull 

 is given in a figure only 16 lines in length, a remnant of the posterior basicranial fon- 

 tanelle can be seen, and this presupposes the absence of the secondary floor at that part. 

 In the gigantic Notornis the basitemporals have their highest development. I had 

 already noticed the extreme thickness of the combined basitemporal mass in the little 

 native Corn-crake ( Crex pratensis), and then in that connecting link between the Rails 

 and Cranes, the Trumpeter {Psophia crepitans), and was therefore prepared to see a large 

 outgrowing mass in this region in a gigantic form of the Rail-type. The outgrowing 

 wings (pterygoid processes) of the basioccipital are repeated again in the basitemporals ; 

 and here, in this Giant Rail, they attain the largest size ever seen in the bird-class ; next 

 to this bird, in this respect comes the King Vulture (Sarcorhamphus papa), and next to 

 that,, the Palamedea (Chauna chavaria) ; but in the latter the basitemporal mass, which 

 is extremely thick, is developed most from side to side. 



Now we saw that, in respect of the basitemporals, the Cassowary came nearest to the 

 ordinary Mammalia ; and the Dinornis is a casuarine Ostrich. This Great Rail, on the 

 other hand, like the King Vulture and the Palamedea, has retained the basitemporal 

 pterygoid processes of the Lizard. Now in the Lacertilia there is the merest shadow of 

 the basisphenoidal "rostrum"; and in. Notornis casuarinus it has about the smallest 

 relative development of any bird that I am acquainted with — far smaller than in the 

 other members of the Rail-tribe. 



great judgment, all merged in the genus Dinomis ; the species are thus very numerous, viz., D. elephantopus, 

 giganteus, ingens, struthioules, rheides, dromidides, casuarinus, robustus, crassus, geranoides, and curtus. Here is 

 B. casuarinus in the very midst of ten stmthious species, and yet as long ago as 1848 Professor Owen well 

 knew that the skiill which he described under that name did not belong to a struthious bird. 



It is but just to remark that the author had some doubts on his mind (see Zool. Trans, vol. iii. pt. 5, pp. 350 

 & 376) as to this matter ; and one would be glad to know whether the term casuarimis has been applied by him 

 to some really struthious fossil, the adze-headed bird being left out of the question. 



