I am now of opinion that a sociable species of rat which was to be found on the Canterbury Plains, near Oxford, in the years 1855–56 was M. maorium. Something of their habits are described in the Transactions, vol. xxiii., p. 195: “Taking a spade and the pointers, we would beat around, and the dogs would presently come to a stand. Going up, an area of some 10ft. would be noticed of a nice green colour among the prevailing brown, being free from tussock [Poa australis], and covered by a small flattish-leaved grass, whose leaves had their points curved or bent towards the ground. At distances apart in this green patch were numerous rat-holes…. From recollection, they [the rats] were reddish-brown, and perhaps white underneath, of a fair size, and not unlike the Norway rat (Mus decumanus). Still, I feel certain they could not be the Norway rat, but a distinct species of a more social disposition, for full-grown ones lived together to the number of eight to fourteen, and were not a family of young rats.” Some four years ago (1890), on reading Mr. Rutland's paper in the Transactions, giving an account of the so-called Maori rat (M. maorium) in the north part of the Southern Island, I set to work to try and find the same rat in the forests here, where I am located—Wimbledon, Hawke's Bay. The grey or brown rats had so great a variety of shades of colour and size that this was no easy matter, and a collection of skins and measurements had to be made of all sorts before I could come to a decision. Ultimately, what I had at first considered to be the young of the larger species (the Norway rat) proved to be entirely distinct, and to have special characteristics peculiar to themselves. This rat (M. maorium?) is coloured brownish-grey, mixed with black hairs; black hairs plentiful from forehead to nose, which is pinkish-skinned; belly, dirty white, also light slate-colour, very dark fur underneath. This white slate colour is often seen on the underside of the wild rabbit in New Zealand, Yellowish-brown stripe down breastbone (not always); coloured on legs down to claws, which are pink, with white hairs; ears are often, or nearly always, jimped as with small excrescences on edges (as if from disease), but this seems a distinct peculiarity of the species; face broad, outline Roman, possibly from hair standing outward naturally; ridge of bone between ears, on back of head, very prominent, sometimes with patches of black colour on the underside of the skin. A second description is: Male, ears jimped with fighting (?), reddish-brown, with black hairs slightly longer; short black hairs on head, giving a stand-up look to the coat, as of an animal very cold or sick (this may be taken as a distinct characteristic of the variety). Nose and mouth pink; under-jaw, belly, inside fore legs, blue-white, with dark under down. Faint bar of reddish