1903.] MEDUSA FROM BRITISH COLUMBIA AND ALASKA. 173 



as ciliated grooves, a condition somewhat like that shown by 

 Haeckel (18, pi. iv. fig, 7, for Catahlema) (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 their 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 Thaxi- 

 mantias 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 porti'ayed by Brandt's 

 (6) figure of Sta^irophora 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-maigin 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 beU-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 sjoecies (2, p. 127, 

 fig. 195). There is also considerable difierence 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 Hai'bour 

 on July 7th 1900, in great numbers; it was abu.ndant 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 diflacult to say in the preserved condition whether this is due 



