The tibia has a length of 17.5in. (445mm.); the proximal width is 4.6in. (117mm.); width of the shaft, 1.4in. (36mm.); and distal width, 2.1in. (53mm.). The antero-external surface is slightly rounded. The distal end of the specimen is unfortunately partly destroyed, but it shows the extremity to be less expanded than in M. casuarina. From the tibia of Megalapteryx the present tibia differs in being more expanded at the proximal end. The femur has an average length of 9.8in. (249mm.); the proximal width is 3.3in. (84mm.); the width of the shaft is 1.4in. (35mm.); and the distal width, 3.5in. (89mm.). The popliteal area is but slightly depressed and not well marked off, by which character it can be distinguished from the femur of Palapteryx plena. The head rises slowly; the linea aspera is fairly well marked, but there is a smooth space between the rough tubercle below the nutrient canal and that on the inner side of the popliteal area. This character distinguishes it from the femora of Mesopteryx, Palapteryx, and Megalapteryx; the popliteal area is also shorter than in Megalapteryx. The shaft is more curved anteriorly than in A. didiformis, but less so than in Megalapteryx tenuipes (Lydekker). From the femur of M. casuarina it can also be distinguished by being slighter, by having a shorter head, and by not being so expanded distally. I append a table of measurements in which are included the leg-bones of an individual skeleton of A. parva, from a cave at Highfield, near Waiau. It will be seen that this specimen has a longer and more slender femur than A. didiformis, the dimensions of which are taken entirely from North Island birds. This, however, seems hardly sufficient to entitle it to rank as a separate species. — Length. Proximal Width. Width of Shaft. Distal Width. Metatarsus. A. fortis 8.0 2.5 1.5 3.5 A. didiformis 6.3 2.1 1.2 2.8 A. parva 6.3 2.0 1.2 2.6 Tibia. A. fortis 17.5 4.6 1.4 2.1 A. didiformis 13.3 3.3 1.1 1.8 A. parva 13.7 3.5 1.2 1.8 Femur. A. fortis 9.8 3.3 1.4 3.5 A. didiformis 8.0 3.0 1.3 3.2 A. parva 8.5 2.8 1.1 3.0