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Show 1903.] MEDUSA F R O M BRITISH COLUMBIA A N D ALASKA. 173 as ciliated grooves, a condition somewhat like that shown by Haeckel (18, pi. iv. fig. 7, for Catablema) (this is not to be confused with the " gastrogenital Kreuz " of Staurostoma). In the preserved condition the walls of the quadrangular stomach are so low that the mouth gapes widely. The crenulated, somewhat twisted, oral fringes are very characteristic, from one to one and a half times the diameter of the stomach in length. The gonads are wavy or serpentine bands depending from the radial canals throughout almost then entire length. Colour.-Bell pale blue, bell-margin and gonads deep violet-blue. Habitat.-Puget Sound, Victoria Harbour, collected by Shearer; Friday Harbour, collected by Kincaid. Discussion.-The general appearance of this Medusa is very like the figure given by Forbes (16, pi. viii. fig. 1 a) for Thaumantias pilosella. The bell is somewhat flatter and the tentacles more numerous, the gonads are also less developed. This flat condition of the bell is very well portrayed by Brandt's (6) figure of Staurophora mertensii (pi. xxiv. fig. 2), which also well represents the number, colour, and appearance of the tentacles. There is a delicate shade of blue through the substance of the bell, so that when in water they would almost escape observation, if it were not for the darker colour of the bell-margin and of the tentacle-bulbs. The colour of the bell so closely matches the blue colour of the sea-water, that the Jelly-fish become indistinguishable, nothing but the dark ring of the bell-margin showing, contracting and expanding as the animals swim. It will be seen that the shape of the bell is somewhat different from that pictured by Agassiz for this species (2, p. 127, fig. 195). There is also considerable difference in size. Agassiz's species measured 3 cm. across the bell; the majority of our specimens measured 5 cm., and some fully 8 and 9 cm.-in fact, were so large that we had no suitable jars in which to place them. Again Agassiz states that the tentacles number about a hundred, whilst in the Victoria examples there are considerably over thrice that number, this last difference being due to increase in size. The number of tentacles in each quadrant of the bell-margin is seldom the same, and not necessarily a multiple of four, no two quadrants have exactly the same number, the average for a quadrant being 84. This species made its appearance suddenly in Victoria Harbour on July 7th 1900, in great numbers; it was abundant for three days, after which few were seen. Agassiz (2) also found it in the region of Puget Sound, July 1859. It is remarkable how readily foreign particles adhere to the bell-surface of this Medusa, little bits of debris, sand, and seaweed sticking to it with great tenacity; many of our specimens were ruined on this account. It is difficult to say in the preserved condition whether this is due |