Zoological Society. 445 



differs from that of the Ostrich and Emeu in the imiDortant character 

 of the absence of the air-hole at the back part of the neck, and the 

 consequent substitution of marrow for air in the interior of the bone. 

 It differs from the femur of the Ostrich, and agrees with that of the 

 Apteryx, in the greater width of the anterior interspace of the con- 

 dyles ; but it differs from that of the Apteryx, not only in size and 

 general proportions, but also in the form of the distal extremity, 

 which has a deejier posterior intercondyloid depression, and a sharper 

 and more i:)roduced posterior part of the outer condyle. 



" The length of the above femur of the great bird of New Zealand 

 is eleven inches ; the circumference of the middle of the shaft five 

 and a half inches : but the present collection includes the shaft of a 

 femur of another individual, with a circumference of seven and a 

 half inches. 



" The most perfect tibia in the present collection measures two feet 

 four and a half inches in length, and apparently corresponds in pro- 

 portion with the fragment of the larger femur. Now allowing that 

 femur fourteen inches of entire length, the tibia is then twice the 

 length of the femur, while in the Apteryx the tibia is only one- 

 third longer than the femur. The larger Struthionida, as the Os- 

 trich and Emeu, more nearly resemble the great New Zealand Bird 

 in the proportion of their tibia, but it is not quite twice the length 

 of the femur in those species. The tibia of the great New Zealand 

 Bird differs from that of the Apteryx and all the large Struthionidce 

 in the complete osseous canal for the passage of an extensor tendon 

 in the anterior concavity above the distal condyles. This osseous 

 canal is commonly found in the tibia of the Gralla, Gallince, Anseres, 

 and many smaller birds. The proportion of length to thickness of 

 the tibia is nearly the same in the Ostrich and the great New Zea- 

 land Bird ; the circumference of the tibia at its proximal end, in the 

 latter, is fifteen inches ; at its middle, five inches. 



" The most instructive bone in the present collection is a tarso- 

 metatarsal bone, with the distal extremity entire, showing that the 

 gigantic bird was tridactyle, like the Emeu, Rhea, and Cassowary. 

 The remains of the proximal end of the bone prove it to have been 

 articulated with a tibia about an eighth part shorter than the one 

 above described, or to a tibia about two feet in length ; the length of 

 the tarso-metatarsal bone is one foot, or half the length of the tibia, 

 which is exactly the proportion which the tarso-metatarsal bone of 

 the Apteryx bears to the tibia. In the Emeu the tarso-metatarsal 

 bone is as large as the tibia ; in the Ostrich it is a little shorter than 

 the tibia. The difference in the proportions of the tarso-metatarsal 

 bone of the gigantic bird of New Zealand and of the Emeu will be 

 obvious from the following dimensions : — 



Dinornis. Dromaius. 



Tarso-metatarsal bone. in. lin. in. lin. 



Length 12 14 6 



Circumference of middle 4 5 2 8 



Breadth of distal end 3 10 2 10 



" The comparative shortness and strength of the trifid metatarsal 



