PROFESSOR OWEN ON THE GENUS DINORNIS. 253 
indicated by a single small foramen (fig. 1,d). The hallucial surface (fig. 2, ¢) is 
barely definable. Along the distal half of the fore surface of the bone the mid meta- 
tarsal shows a recognizable prominence. The distal end of the bone closely adheres to 
the dinornithic type; the depressions 77’, iv’, figs. 3, 4, are well marked; the condyles 
Il, 1, Iv have the usual dinornithic proportions and relative positions. The digits 
aw, vi, w have the usual phalangial formule; the mid toe (iii) is longer in proportion 
to the metatarse than in Dinornis robustus', but is shorter in proportion to the digits 
vi, iv; the ungual phalanx of each toe is rather sharper and more decurved than in 
the larger species. 
§ 13. Phalanges. 
For comparison of the foot-bones of Dinornis parvus with those of Dinornis rheides, 
reference may be made to plate iii. of Memoir, part iv. Trans. Zool. Soc. vol. iv. 1851, 
and with those of Dinornis dromoides to plate ii. of the same part and volume. It 
will be seen that the smaller species under description shows intermediate proportions 
of the toes in regard to thickness and length. 
In the absence of any definite indication of an articular surface for the innermost 
toe, it might have been inferred that Dinornis parvus, like some larger species, to which 
I therefore originally limited that generic appellation, had lacked that part of the foot— 
a part which, being better developed in other species, led to their being referred to a 
genus Palapteryx. But the degree in which the digit 7 (Pl. LVII. figs. 8, 9) may be 
reduced without being wholly lost, is significantly demonstrated by the subject of the 
present ‘ Part,’ owing to the care with which the bones of the individual, dying in the 
cavern most probably a natural death, were collected. 
§ 14. Conclusion. 
If the skeleton of Dinornis parvus (Pls. LI. & LVIII.) be compared with those of 
D. maximus, D. robustus, D. crassus, D. rheides, D. gravis, D. didiformis, D. gracilis, 
and D. casuarinus*, it will be seen that the smallest species (Pl. LVIII. of the present 
Part) has proportionally the largest skull. The modifications of tne frame accompanying 
augmentation of bulk in the genus, are chiefly manifested by greater proportional 
length and strength of the terrestrial limbs. If the peculiarly nutritious roots of the 
common ferns of New Zealand contributed, with buds, foliage, or other parts of trees, 
to the food of the gigantic race, the concomitant gain of power in the locomotive and 
fossorial limbs seems not to have called for a proportional growth of brain or of bill. 
’ Trans. Zool. Soc. vol. iii. p. 47, pl. i. 
7 “Memoirs on the Extinct Wingless Birds of New Zealand,’ 4to, vol. ii. 1878, ls. xevi., xcvii., cyiii.—cxii} 
