
283 
The figures, of the natural size, im Pl, LXXXIL., in which each b 
bolic nyraber, with similar figures in the present and former Memoirs of oth er species of 
Dinornis, give grounds of comparison which preclude the necessity of further verbal 
notice of details. One notes with interest that a species with comparatively long and 
slender limbs om the present wingless genus has a more lengthened beak (e.g. Dinornis 
ingens) than Dinornis crassus, and that the diploé of the cranial walls is less thick, 
showing the more than usually domed character of the cranium? in this broad and flate 
headed group of extinct birds, The range in the length of the rostral part of the pre- 
maxillary exemplified by Linornis crassus and Dinornis ingens, indicates a ground of 
derivative variety in which the existing Apteryx exemplifies a maximized degree. But, 
unless this gain was sudden in the dwarf species, the intermediate steps should be 
numerous, and have not yet been observed. 
In the ‘ Bericht tiber einen fast vollstindigen Schidel von Palapteryx,’ Dy. Gustav 
Jaeger compares his specimen with the several figures of the skulls of New-Zealand 
extinct wingless birds given in the 5rd volume of the ‘Transactions’ of the London 
Zoological Society, pls. 38, 39, 52, 93, 55, but appears not to have been cognizant of 
the Memoir in the 4th volume (p, 205), in which not only is the most complete skull 
of a Moa described and figured which had, at that date (1850), been obtained, but 
also one belonging to the same species as that to which Dr. Jaeger is finally led to refer 
the subject of his description. (See ‘‘ Erklirung der Tafel xxv., Schiidel von Palapteryx 
ingens, Ow.,” at the close of the Memoir.) 
The chief aim of the comparisons of the accomplished Director der Wiener 
Thiergartens is to show that his specimen exemplifies the generic characters of Pala- 
pteryz by contrast with those of the skull referred, erroneously, by me to Dinornis 
casuarinus, in my third Memoir (1848), p. 445, pl. 52. vol. ii, Trans, Zool. Soc. That 
skull I now believe to have belonged to the Dinornis otidiformis of the first Memoir 
(p. 73), founded on a tibia (Pls. XXV., XXVI. fig. 5), but recognized by the subsequent 
acquisition of the metatarsal as a distinct genus, Aptornis, belonging to a distinct family, 
perhaps order, of birds from that to which Dinornis belongs. Upon that rectification I 
lost the best ground on which I had previously based the generic distinction of Dinornis 
from Palapteryx ; and now there remain the degree of development of the abortive and 
functionless back toe, which I cannot regard of generic importance, and the proportions 
of sternum, limb-bones, and rostral part of the beak-bones, all more or less gradational. 
With the breadth of trunk concomitant with limbs so robust and divergent as in D. 
robustus, D. elephantopus, and D. crassus, the sternum is broad in proportion to its 
length, and the side processes more divergent; yet the dinornithic type of that bone 1s 
closely kept. 
The robuster-limbed and broader-bodied Moas, 
* This character of the skull of Dinornis ingens is somewhat exagg 
(Taf. xxv, op, cit.), through the yiew in fig. 1 not being a direct profile but 
one bears its sym- 
however, do not all show the short, 
erated in Dr. Gustav Jaeger’s figure 
looking obliquely on the calvarium, 

