380 PKOr. T. JEPFEET PAKKEK OJST THE CEANIAL OSTEOLOGY, 



4. Emeus, species y. 

 The cranium on a skeleton from Hamilton Swamp, named D. gravis by Prof. Hutton. 

 (Otago Univ. Mus.) 



This skull agrees in general characters with the present genus, but has right- 

 angled orbits — a character I have never observed in any of the preceding species. 

 Figured in outline, Plate LXI. figs. 34 & 40, and Plate LXII. fig. 58. 



3. A Comparative Account of the Skull in the Dinornithid^e. 



The skulls of the Moas are usually found in a more or less fragmentary condition, 

 and it will be advisable, for the sake of convenience, to take this circumstance into 

 consideration and to describe the skull under the following heads : — 



a. Cranium. 



b. Premaxilla. 



c. Maxillo-jugal arch. 



d. Vomer, palatine, and pterygoid. 



e. Quadrate. 

 /. Mandible. 

 g. Hyoid. 



The cranium is the part most commonly found • in large deposits of Moa-bones 

 crania may occur in hundreds, whilst other portions of the skull are of comparatively 

 rare occurrence. Premaxillse, quadrates, and lower jaws are not uncommon, while a 

 complete maxillo-jugal arch is rare, and very few skulls have been found with the 

 palatines, pterygoids, and vomer uninjured. 



a. The Cranium. 

 In the cranium the following regions may be distinguished : — 

 i. The occipital region, including the whole posterior portion of the skull ; it contains 



the occipital condyles and foramen and is produced at the sides into the large 



and prominent paroccipital processes. 

 ii. The cranial roof, continuous behind with the occipital region, 

 iii. The base of the skull, also continuous behind with the occipital region; posteriorly 



it is raised into a prominent squarish elevation, the basitemporal platform ; 



anteriorly it is continued into a more or less cylindrical rod of bone, the 



rostrum, which forms the axis of the beak. 

 IV. The lateral surface of the cranium, presenting three well-marked depressions — the 



orbit in front ; the temporal fossa immediately behind the orbit and separated 



from it by a downward projection of the skull-roof, the postorbital process ; and 



the tympanic cavity, bounded above and separated from the temporal fossa by 



an outstanding mass of bone, the squamosal prominence, and bounded behind 



by the paroccipital process. 



