The Structural Characters of Te Anau Salmon By G. Stokell [Received by the Editor, May 7, 1958.] Abstract Comparison of structural features shows that the freshwater-dwelling salmon of Lake Te Anau agree more closely with normal Salmo salar than with the lake-dwelling forms known as ouananiche and sebago. The conclusion that the Te Anau salmon have been derived from sea-going salmon is supported by analagous structural modifications in lake-dwelling Oncorhynchus tschawytscha. The American forms, ouananiche and sebago, which have been regarded as subspecies or varieties of Salmo salar, are reinstated as a distinct species under the original name of Salmo sebago Girard. Introduction The voluntary freshwater existence of Salmo salar at Lake Te Anau was dealt with by the writer in 1934, since when no evidence of a sea-going habit has been observed and nothing has occurred to affect the position as stated. The fish exists throughout Lakes Te Anau and Manapouri, in the Waiau channel between them and at Lake Gunn, on the upper Eglinton. All of these waters are in the valley of the Waiau River, which is possibly the second largest river in New Zealand. It has its source in the outlet of Lake Te Anau, 53 miles in a direct line from its mouth, but some 75 miles by way of the river channel. Above this nominal source there is a large drainage basin extending back for over 40 miles, a considerable part of which ranges from 4,000ft to 6,000ft in altitude and receives a rainfall of from 50 inches to 100 inches annually. Lake Manapouri, which is about 17 miles in length, has an altitude of 599ft and has been sounded to 1,455ft. It receives the drainage from Lake Te Anau in addition to numerous streams in its own catchment area, and discharges at the south-eastern corner about seven miles from where the Wauau channel enters it. Lake Te Anau is separated from Lake Manapouri by about 15 miles of river channel. It is about 36 miles in length, has an altitude of 679ft, and has yielded soundings of over 900ft. On the west these lakes have great arms similar to the ice-cut fiords of the western sea coast and apparently formed in the same manner. Lake Manapouri is surrounded by mountains and dense bush, and Lake Te Anau is of similar character on the western side, but a considerable part of the eastern shore is low and scrub-covered. Lake Te Anau has numerous tributaries, the largest being the Eglinton River, which enters the lake about half way along its eastern shore and drains. Lake Gunn some 25 miles upstream. Lake Gunn, which is about two miles in length, has an altitude of 1,575 feet and is heavily bushed. Its water is slightly stained, as is that of Lake Manapouri and, to a less extent, that of Lake Te Anau also, but none of these lakes is ever turgid except for local discolouration in the vicinity of flooded tributaries. The fishes known from this locality are: Native. Introduced. Retropinna obtusirostris Stokell Salmo trutta Linnaeus Galaxias lynx Hutton sub sp? Salmo salar Linnaeus Anguilla dieffenbachii Gray Salmo gairdneri Richardson Gobiomorphus basalis Gray All of these occur in Lakes Te Anau and Manapouri, but only Galaxias lynx and Gobiomorphus basalis have been collected by the writer at Lake Gunn. The