The phalangeals of the pes are much shorter and stouter than in _Dinornis_, the proximal surface of the terminal segments generally presenting a trefoil-shaped contour. The length of the tarso-metatarsus is very much {214} less than half that of the tibio-tarsus. In the vertebral column the cervicals are short with very stout centra, the prezygopophyses in the middle region being nearly horizontal and separated from one another by a wide channel. The posterior face of the centra is tall and narrow, and the neural spines of the last two vertebrae much inclined forward. In the dorsals there is usually no anterior pneumatic foramen till the fourth (or the last with a distinct haemal carina), this foramen being situated on the line of the anterior border of the rib-facet. The third and fourth dorsals are extremely compressed. Throughout the series also the neural spines and transverse processes are comparatively long. Additional characters of the skull are that the sphenoidal rostrum is expanded in a lance-like shape at the anterior extremity, in a manner unlike that of any of the other genera. Then the supraoccipital never has a very strongly developed median prominence, and the temporal fossae are comparatively short. The mandible may be readily distinguished from that of the other genera by the low position of the inner aperture of the dental canal, which pierces the bone obliquely to join the small lateral vacuity. Type of the genus: _Pachyornis elephantopus_ (Owen). Number of species: 8. PACHYORNIS ELEPHANTOPUS (OWEN.) _Dinornis elephantopus_ Owen, Trans. Zool. Soc. IV, p. 149 (1853). _Palapteryx elephantopus_ Haast, Ibis, Ser. 3, vol. IV, p. 212 (1874). _Euryapteryx elephantopus_ Hutton, Trans. N.Z. Inst. XXIV, p. 135 (1892). Until Mr. Lydekker described _Pachyornis immanis_, and Mr. Andrews _Aepyornis titan_, this was undoubtedly the most bulky and ponderous of all known Ratitae, extinct and living. Type: Awamoa, near Oamanu. Habitat: Middle Island, New Zealand. Two imperfect skeletons in the Tring Museum; one from Kapua Swamps. {215} PACHYORNIS IMMANIS LYD. _Pachyornis immanis_ Lydekker, Cat. Foss. Birds Brit. Mus., p. 343 (1891). This is the most bulky and largest member of the genus, and also of all _Dinornithidae_. Its living parallel to-day is _Casuarius philipi_ Rothschild, which, though by no means the tallest species of _Casuarius_, is the most bulky, and has the shortest and stoutest legs--the tarso-metatarsus is specially short and stout. The type tarso-metatarsus measures 228 mm. = 8.9 inches, and in width (shaft) 84 mm. = 3.3 inches, while the type tarso-metatarsus of _elephantopus_ measures 239 mm. = 9.4 inches and 65 mm. = 2.55 inches. The skull is much more depressed than in _elephantopus_ and with deeper temporal fossae and a shorter post orbital region. Type: No. A168 British Museum. Habitat: Middle Island, New Zealand.