PROFESSOR OWEN ON THE GENUS DINORNIS. 163 



coalesced coccygeals in birds of flight, for the support of the rectrices, or steering quill- 

 feathers of the tail. 



The cranium is six inches eight lines in length ; three inches nine lines across the 

 broadest part, behind the orbits. The post-orbital process is broad, compressed, and 

 descends nearly to the zygomatic arch. The upper mandible is slightly deflected, 

 conical, obtusely pointed, with the external nostrils terminating at the distance of about 

 an inch from the apex of the premaxillary. The upper part of the'median nasal process 

 of this bone, together with the nasals, has been broken away. The minor characters 

 of the cranium and of the lower mandible accord generically with those of the Dinornis, 

 described in the present volume of the ' Transactions of the Zoological Society,' 

 pp. 60-65. The chief peculiarity of the skull in the present species is its small size, as 

 contrasted with the pelvis and hind limbs. 



The characters of the bones of the leg and foot of the Dinornis elephantopus have been 

 described in a preceding memoir, and need not here be repeated. 



The keel-less sternum, in its shortness, breadth, and subquadrate form ; in the two 

 wide and deep posterior notches ; in the unusually small and shallow coracoid fossie ; 

 and in the reduction of the articular pits on the costal borders to three on each side, 

 closely conforms to the type of that instructive bone, in the Palapteryx (Dinornis), 

 described in the fourth volume of the ' Transactions of the Zoological Society,' 

 pp. 194, 195. 



I have refrained from entering into closer descriptive details of the skeleton of the 

 Dinornis elephantopus, because only the plates can convey an adequate idea of its extra- 

 ordinary proportions to those who have not seen the original itself. 



The specimen, as now articulated, stands in the first compartment of the Palajontological 

 Gallery of the British Museum. The articulated hind-limbs of the Dinomis {robiistus) 

 are placed on each side, as in PI. XLVIL, to illustrate the characteristic proportions of 

 the two extinct species. 



The drawings from which the plates have been engraved were taken from two 

 successful photographic views, corrected, as to the relative size of the parts, from the 

 skeleton itself: I am much indebted for the care and skill which Mr. Erxleben has 

 bestowed on this complex subject. 



The bones which have served for the reconstruction of the skeleton of the Dinornis 

 elephantopus were selected from the large collection obtained by Mr. Commissioner 

 Mantell, in the Middle Island of New Zealand, at the locality (Ruamoa, Middle Island 

 of New Zealand) and under the circumstances described in the preceding memoir. 



