to its former channel. I would have a number of large stones in the bottom of the pond to provide hiding-places, as the trout of all ages seem inclined to lie quiet during the day, and come out at dusk to rove about. While kept in the pond they should be fed regularly. I have pleasure in adding that I have been greatly indebted to Mr. Ayson, of the Wellington Acclimatization Society, at Masterton, from whom I have received much valuable information, and small parcels of trout for experimental purposes.

Art. XXVIII.—The Distribution and Varieties of the Fresh water Crayfish of New Zealand. By Chas. Chilton, M.A., B.Sc. [Read before the Otago Institute, 11th September, 1888.] Plate X. For some years past I have been engaged, whenever opportunity offered, in forming a collection of freshwater crayfish from the various parts of New Zealand, with a view of determining exactly how many species were represented, and what varieties of these species, if any, existed. By the assistance of several friends I have succeeded in getting a fairly representative collection from both islands, and I now give the somewhat meagre results that I have arrived at from the examination and comparison of specimens from the various localities. It will be well first to state briefly what has been previously written on the subject. Miers, in his catalogue of the stalk- and sessile-eyed Crustacea of New Zealand (pp. 72, 73), published in 1876, gives three species of freshwater crayfish as inhabiting New Zealand—viz., (1) Paranephrops planifrons, White (including under this P. tenuicornis, Dana), (2) P. setosus, Hutton, and (3) P. zealandicus, White. P. planifrons is well known from many parts of the North Island, and P. setosus from the Avon, in North Canterbury, and from other localities in the South Island; but P. zealandicus does not seem to have been with certainty recognised since it was originally described by White. It was described in 1847, and as I have already stated in a previous paper,* “Trans. N. Z. Inst.,” vol. xv., p. 151. Professor Hutton, who described his P.