26 OCEANIA, 
Genus IV. OcrEAntA (nom. Peron), (1809). 
TiARA and Oceania (pars), Lesson. 
Umbrella conical, mitrate, or rarely globular; ovaries four, double, convoluted, 
lining the cavity of the peduncle; vessels simple, four; margin of the umbrella with 
few, or many, similar tentacula; no conspicuous muscular bands; mouth of the 
peduncle four-lipped. 
The natural wish to preserve a name in a manner consecrated by long usage, has induced 
me to retain that of Oceania, even at the risk of employing it in a somewhat different generic 
signification from any of the many meanings hitherto given to it, and thereby perhaps almost 
increasing confusion. In such a case it becomes a toss-up whether the conservative or the 
destructive process be best; but as even the most virulent of reformers gladly seize on an 
excuse for upsetting usurpers, whilst good-natured people are mclined to stand by ancient 
dynasties, however bad, rather than risk the chances of change, I think it safest (though 
prepared to do either) to adopt Oceania as a genus for the present, and, by defining it more 
strictly, endeavour to make it more useful. 
The term Oceania has been so often and generally applied to the Medusa pileata of 
Forskal, and similar forms, that I think it best to restrict it to that group. Peron, who first 
founded the genus, included them within it, though it is doubtful whether he would have 
regarded the Forskalian species as the type. Lesson gives the generic name of Tvzara to 
M. pileata ; and those who are extremely anxious to use a new name may adopt it. Eschscholtz 
included its allies in his view of the genus, but also some very distinct forms. _ 
Using it in the sense here taken, the genus consists of those mostly mitre-shaped 
Meduse, which have an ample dependent peduncle and convoluted ovaries within, a conspicuous 
character indicating a close relationship with Zurrzs. Their muscular tissue, however, is not 
nearly so highly organized as in the last-named genus, whilst the uniform character of the 
tentacles separates them from Saphenia. 
The species of Oceania range throughout the European seas, extending into the 
Mediterranean. ‘They will probably be found much more numerous than at present recorded. 
Sars has described and figured in his ‘ Beskrivelser, &c., 1835, a species with twenty-four 
tentacula, and resembling in form our O. episcopalis, which may probably inhabit our seas. 
He names it O. ampullacea, and describes it as ovato-campanulate, terminating above in an 
oblong, conical appendage; the mouth furnished with very short fimbriations ; the length of 
the body about an inch. Forskal’s name of ‘‘ Medusa pileata’ has been applied to more than 
one species of the genus. He described it as “ ovato-campanulate, terminated above by a 
hyaline sphere ; within containing an oblong, red nucleus; the margin fringed with numerous 
tentacula, having yellow bases.” His figure does not show clearly the number of tentacula, 
but they appear to have been sixteen and upwards. The animal figured by Ehrenberg as 
Medusa pileata from the Norwegian seas, has a yellow nucleus, and appears to be the 
Oceania ampullacea. The colour of the nucleus, the general form of the umbrella, and the 
number of the tentacula, are evidently the most important sources of character in this genus, 
and should be carefully noted. 
