\ 



250 PROFESSOR OWEN ON THE GENUS DINORNIS. 



Apteryx and the three species of Dinornis, as above restored, are given in the subjoined 

 table. 



Ostrich. Emeu. Apteryx. D.giganteusK D.struthoides'^. D. didi/ormis'. 



/I. /I2. /8. 



Circumference of ditto. .37 30 00 56 43 36 



It will be seen that in these three species of Dinornis the united lengths of the femur 

 and metatarsus equal or nearly equal that of the tibia, and that the metatarsus is rela- 

 tively shorter and thicker as the species decrease in size. 



The femur / 2 and the tibia i 2 of the Dinornis ingens have no metatarsus to match 

 them in the present collection : such a metatarsus should be fifteen inches in length. 

 Whether the Dinornis with a hind-leg of these proportions be actually a distinct species 

 from the Dinornis giganteus, or a smaller individual on account of age or sex, is a 

 question which, though the present evidence induces me to answer in the afBrmative, I 

 should be glad to see confirmed by additional specimens. 



With respect to the smaller femora, especially those numbered f 7,f 8,f 17, if they 

 had belonged to the young birds of the larger species, their nonage would unquestionably 

 have been indicated by the characters of the bones. The femur of a young Ostrich, 

 bearing the same proportion to that of the adult which/ 7 bears to/ 12, has the whole 

 upper surface of the proximal end and all the distal articulation covered with thick car- 

 tilage, and the line of the terminal epiphysis is conspicuous, although the uniting ossifi- 

 cation has commenced ; the trochanterian ridge is rounded ofi"; the surface of the shaft 

 of the bone is smooth ; the muscular ridges quite undeveloped. In the small femora 

 of the Dinornis, /7,/8,/ 17, no trace of the separation of the terminal epiphyses 

 remains ; the sculpturing of the articular surfaces is sharp and bold ; every ridge and 

 tuberosity indicative of muscular action is as strongly developed as in the largest 

 femora. 



The same characters establish the maturity of the femora/ 6 and/ 16 ; / 13 has the 

 muscular ridges and prominences less strongly developed. There are no tibise or me- 

 tatarsi which, upon the analogies and proportions adopted for the collocation of the 

 principal bones of the leg in the Dinornithes giganteus, ingens, struthoides and didiformis, 

 can be assigned to these femora. Regarding which, therefore, it is first to be inquired 

 whether they belong to immature individuals of Dinornis struthoides or to a distinct sex 



' PI. XXX. fig. 1. « Ih. fig. 2. ' lb. fig. 4. 



