C. W. NASH.
THE following list includes all the fishes found within a radius of ten or twelve miles from the city of Toronto of which I have authentic records.
MARSIPOBRANCHII. (The Lampreys.)
1. Silver Lamprey. Lamper Eel. Icthyomyzon concolor (Kirtland).—The Silver Lamprey is abundant in Lake Ontario, usually in deep water, but it runs up the small streams to spawn in the spring. It is a most destructive parasite on the large commercial fishes, fixing itself to their bodies by means of its suctorial disk and causing deep ulcerated wounds at the point of attachment, which very frequently result in death. When spawning they form nests in the bed of the stream among cobble-stones and pebbles; in these the eggs are deposited, after which the parent fish all die. After emerging from the eggs the larvae burrow in the mud or sand near the margin of the stream and there remain in the larval condition, blind and toothless for a long period,