426 Proceedings. 
And I might add here another important peculiarity in these two main 
divisions, which was first pointed out to me by Mr. Fuller, and which is of 
great practical value when examining even the smallest bones. Mr. Fuller has 
found that in the mere handling of the bones a great difference is at once to be 
detected amongst those coming from the very same spot. Thus the remains of 
Palapteryx are harder, and have resisted more effectually the influence of time 
than those of Dinornis; the exterior dense crust is far stronger and thicker 
and is less smooth than in the latter. Moreover, the bones of the Palapterygide 
are not quite so porous as those of the Dinornithide, and consequently are 
heavier in proportion. 
After these few introductory observations I now proceed to lay before you 
the scheme after which I propose grouping together the different species of 
our extinct struthious birds, giving, at the same time, some of the principal 
distinctive features of each group :— 
A, Family DINoRNITHIDZ. 
a. Genus Dinornis. 
Metatarsus long, no hallux, pelvis narrow, sternum longer than broad, 
convex, with constant and well-marked coracoid depressions for the scapulo- 
coracoid bone; narrow and straight anterior crest, costal processes slightly 
developed, lateral processes standing at less angle than in the Palapterygide. 
Existence of a bony scapulo-coracoid ; beak narrow and pointed, three inter- 
costals; skeleton altogether of a more slender stature than any of the 
Palapterygidee. . 
1. Dinornis maximus. 
2. Dinornis robustus. 
3. Dinornis ingens. 
4. Dinornis struthioides. 
5. Dinornis gracilis. 
b. Genus Meionornis.* 
Metatarsus long, no hallux, pelvis narrow like Dinornis, and the whole 
skeleton altogether more slender than any of the Palapterygidæ. Sternum 
convex, longer than broad, with a broad and well-curved anterior border ; 
costal processes well developed, no coracoid depressions ; bony scapulo-coracoid 
absent, beak well pointed and even narrower than in Dinornis. 
l. Meionornis casuarinus. 
' 2. Meionornis didiformis. 
D. Family PALAPTERYGIDJE. 
а. Genus Palapteryx. 
Metatarsus very short and broad, with hallux and hind toe ; distal trochlex 
* From meion, less ; and ornis, bird. 
