1903,] MEDUSA FROM BRITISH COLUMBIA AND ALASKA. 183 



tentacles are not rolled in and contracted, this Mednsa is evidently 

 a species of Mesonema. Great difficulty was fonnd in preserving 

 our specimens ; they seemed to become very brittle on shoi't pie- 

 servation by the ordinaiy method in formalin, the slightest shaking 

 of the bottle in which they were preserved causing them to break 

 up into small fragments ; the majority of our jars reached home 

 with nothing but a mass of debris at the bottom.. This Medusa 

 was quite common about Victoria during July, and is evidently 

 as abundant on the opposite shore of Puget Sound, being repre- 

 sented by numerous examples in Prof. Kincaid's collection from 

 the vicinity of Port Townsend. When kept in captivity they can 

 be readily observed opening the mouth widely right back to the 

 commencement of the radial canals and then rapidly closing it 

 again, wrapping the oral lobes into a corkscrew-shaped mass, 

 as Haeckel (18) has represented the oral lobes in his plate of 

 Pohjcanna f angina (pi. xiv. fig. 4). This may be i^epeated rapidly 

 over and over again. Possessing about an equal number of radial 

 canals and tentacles, this species comes under Haeckel's subgenus 

 Mesonemella, but is difierent from either of his two species 

 M. eurystoma and 3£. cyaneum [Zygodactyla cyanea of Agassiz). 

 Nor does it agree with Fewkes's new species (13), M. hairdii, 

 because in this there ai'e four times as many radial canals as 

 tentacles. 



C. TRAOHOMEDUS^. 

 I. Petasid^ Haeckel. 

 GoNiONEMUs A. Agassiz. 

 1. GoxioNEMUs vertejSTS A. Agassiz. 



Specific description. — The bell is described by Agassiz as " an 

 oblate spheroid cut in two by a plane passing through the noith 

 and south poles, the plane of intersection containing the circular 

 tube." He also gave other features that will be embodied in this 

 account. Preserved specimens are 1"75 cm. tall and 1'50 cm. 

 broad, being about the same size during life. The bell is consider- 

 ably taller than a hemisphere, is rather thin, and tinged a yellowish 

 green during life. There is a slight conical depression in the roof 

 of the stomach. The velum is well developed and rather broad 

 stretching almost halfway across the opening of the subumbrellar 

 cavity. The tentacles are twice the longest diameter of the bell 

 in length, and look wiry and vSomewhat heavy for the size of the 

 animal. They show the ringed welts of nematocyst well developed, 

 standing out very prominently. There ai'e no true tentacle-bulbs, 

 the tapering ends of the tentacles being inserted directly in the 

 bell-mai'gin ; but below their insertion thei-e are rather large, 

 oval, brown basal papilhe. Some distance from the outer end of 



