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Show 206 PHOF. W. B. BEXHAM OX AQUATIC [Nov. 3, Analysis of the Oligochcete Fauna of each of the Lakes. Lake Wakatipu, South Island. Greatest depth, 1242 feet. Number of stations at which worms were obtained, 10. Total number of specimens, 37. The commonest worm appears to be Plutellus lacustris, which was obtained from 7 stations at different parts of the lake, so that it is evidently widespread throughout; but it appears to be limited to this lake, as none were obtained elsewhere. Phreodrilus lacustris also occurred at three stations, and appears to be somewhat less widely distributed, though living at the same depth. Hapilotaxis heterogyne was obtained only at one station, and a single undetermined immature specimen of Limnodrilus. Lake Manapouri, South Island. Greatest depth, 1458 feet. Number of stations, 6. Number of specimens, 16. This, the deepest lake, so far as this survey is concerned, contained a greater variety of 01igocha?tes than any of the other lakes, for it yielded 6 genera. Phreodrilus lacustris and Taupodrilus simplex account for twelve out of the sixteen specimens ; the former was obtained once only, the latter at two stations. At two other stations Biporochceta aquatica and at another Achceta maorica were captured, while an immature Limnodrilus completed the list. Lake Taupo, North Island. Greatest depth, 534 feet. Number of stations, 4. Total number of specimens, 32. Taupodrilus simplex and Limnodrilus lucasi account for more than two-thirds of the total, the former occurring in two hauls, the latter in one only. With the former, Phreodrilus mauianus was obtained, while at another spot Enchytrceus simvlans occurred, and an undetermined species of Tubifex completes the list. Lake Rotoiti, North Island. Greatest depth, 228 feet. Number of stations, 2. Number of specimens, many. This lake is characterised by Limnodrilus lucasi, of which 3 or 4 dozen were obtained at one spot; while at the other station immature specimens of Tubifex occurred. Lake Waikaremoana, North Island. Greatest depth, 846 feet. Number of stations, 3. Number of specimens, 16. Unfortunately these were very poorly preserved, much broken |
