PACHYORNIS PONDEROSUS (HUTT.)
Euryapteryx ponderosus Hutton, Trans. N.Z. Inst., p. 137 (1892).
This species is slightly smaller than P. elephantopus, the tarso-metatarsus varying from 8.25 to 8.0 inches, as opposed to from 9.4 to 9.25 in elephantopus; the tibio-tarsus varies from 18.5 to 18.6, as opposed to 24 to 24.1; femur, 10, as opposed to 13 to 11.8.
The skull can be distinguished by the processes at the hinder angles of the basi-sphenoid, which are higher and rounder in ponderosus, flatter and more elongated in elephantopus. Type: Hamilton.
Habitat: Middle Island, New Zealand.
Cast of egg in Tring Museum, taken from specimen in Otago Museum, dredged up in 1901 in the Molyneux River, also incomplete skeleton from Kapua Swamps.
PACHYORNIS INHABILIS HUTT.
Pachyornis inhabilis Hutton, Trans. N.Z. Inst. XXV, p. 11 (1893).
Differs from ponderosus by having the great inward expansion at the distal end of the tibio-tarsus. This expansion has induced some ornithologists to separate the species of Pachyornis into two genera—Euryapteryx and Pachyornis—but I do not think this expansion of sufficient importance to warrant generic separation.