PROFESSOR OWEN ON THE GENUS DINORNIS. 251 
In the immature individuals of Dinornis, not much exceeding in size the present 
mature example of D. parvus, the proximal epiphysis is seen to consist chiefly of the 
epicnemial process with the upper portions of the procnemial and ectocnemial ridges ; 
the epiphysis, also, includes the outer of the two tuberosities for the attachment of the 
intercondylar ligaments. The broad articular surface for the inner femoral condyle, 
and the tuberosity for the outer one, are formed by the diaphysis. 
The distal epiphysis of the tibia includes both condyles of the articular pulley, 
including the whole articular surface, and also that portion of the shaft which forms 
the outer (fibular) wall of the canal for the extensor tendon, including the tuberosity 
giving attachment to the same end of the ligamentous bridge, which subsequently 
becomes ossified. A foramen marks the remnant of the outer (fibular) part of the 
suture between the diaphysial process of the epiphysis and the rest of the shaft of the 
tibia. The anterior extension of the epiphysis, for a considerable extent upon the 
diaphysis, is shown in fig. 4, pl. lix. of the Memoir on Dinornis gravis’, and negatives 
the homology of this characteristic avian epiphysis with the ‘astragalus,’ or other 
proximal tarsal bone in Reptiles. From the distal epiphysis is developed the groove 
and bridge for the tendon of the ‘ tibialis anticus.’ 
§ 10. Patella. 
Only in the present complete skeleton have I found the patella of a Dinornis pre- 
served (Pl. LVIII., bones of the right leg). It is an oblong triedral bone, the outer or 
front side being the broadest, slightly convex, and rather rough; the other two sides 
are smooth, as if originally coated by cartilage. The surface next the outer femoral 
condyle is moderately sinuous; that next the inner condyle is flat transversely, concave 
lengthwise at the proximal two thirds, convex to the deflected small end. The length 
of the patella is 1 inch 1 line, its breadth 7 lines. 
§ 11. Fibula. 
The proximal end of the fibula (Pl. LVI. fig. 7) contributes, as in other birds, to the 
articulation with the outer femoral condyle; its breadth is 1 inch 4 lines. On its 
inner (tibial) side the articular surface (ib. @) is continued upon the shaft for an extent 
of 4 lines. Below this part the bone rapidly contracts, takes on a triedral form, the 
hinder and inner angle articulating with the fibular ridge of the tibia. On the opposite 
side of the bone is an elongate rough surface for the origin of the ‘ peronzeus medius’ 
muscle*. Beyond the tibial conjunction the fibula more rapidly contracts, and termi- 
? Trans. Zool. Soc. vol. viii. 
? « Accessorius flexoris digitorum,’ Vicq d’Azyr. See “Anatomy of the Aptery«,” part ii. (Myology), Trans. 
Zool, Soc. vol. iii. p. 297, pl. xxxii. fig. 1, 12. 
2Q2 
