THAUMANTIAS HEMISPH MRICA. 49 
13. Thaumantias Thompsoni, Forbes (1841). 
Plate XI, Fig. 5. 
E. Forbes, in Annals of Natural History, April, 1841, p. 88, pl. 1, f. 6. 
Among the most phosphorescent of the smaller Medusze on the coast of Cornwall, and 
elsewhere in the south, is a little Thawmantias, which several years ago (in 1840) was met 
with, for the first time, by Mr. W. Thompson, Mr. R. Ball, and myself, in Clifden and 
Roundstone Bays, on the coast of Connemara, in Ireland. When irritated, it gives out a 
brilliant light from the bulbs of its tentacula. 
The umbrella of Thaumantias Thompsoni is hemispherical and rather depressed, smooth 
and colourless. It measures about a quarter of an inch across. Round its margin are sixteen 
(3X4-+-4) white tentacula, springing from rather large yellow tubercles, each bearing a very 
small, dark red or nearly black ocellus. These tentacles, when highly magnified, appear 
annulated, and their bulbs distinctly exhibit an ocellus separate from an otolitic mass. The 
sub-umbrella is rather more depressed than the umbrella. On its sides, rather more than 
half way down, are the four reproductive glands, ovate, and of a clear yellow colour. In the 
centre is the small, rather slender, quadrangular stomach, also yellow; it terminates in four 
triangular lips, margined with a thick band of fibrous cells. 
Plate XI, f. 5, a and 4, represents this species magnified ; 5, e, one of the ovaries full of 
egg, and the bulb of a tentacle, greatly magnified ; 5, d, part of the margin with three ten- 
tacula; 5, e, a lip, with its border of fibrous cells. 
14. Thaumantias hemispherica (sp.), Miller (1776). 
Plate VIII, Fig. 2. 
Synonyms. Medusa hemispherica. Gronovius, Acta Helv., 438, t. iv, f. 37 (1760). 
O. F. Miiller, Prod. Faun. Dan., No. 2822 (1776). 
——— O. F.‘Miiller, Zool. Dan., pl. 7, f. 1-4 (1788), 
(fig. Cop. in Enc. Meth., pl. 93, f. 8-10.) 
——— Lin., Syst. Nat. Cur. Gmelin, p. 1098 (1789). 
——— Modeer, Kong. Vet. Ac. Nya Kand. vol. xii, 
p- 251 (1791.) 
Oceania hemispherica. Peron, Ann. de Mus., vol. xiv, p. 347 (1809). 
Medusa hemispherica, var. lucida. Macartney, Phil. Trans. (1810), 
p- 264, pl. 14, f. 3. 
Geryonia hemispherica. Fleming, Brit. Animals, p. 500 (1828). 
Thaumantias hemispherica. Eschscholtz, Syst. der Acal., p. 103 (1829). 
Blainville, Man. d’Act., p. 285 (1834). 
SSS=5 (Lamarck), An. sans Vert., 2d Ed., 
p. 162 (1840). 
Medusa (Geryonia) hemispherica. Thompson, Annals of Nat. Hist. 
vol. v, p. 248 (1840). 
Thaumantias hemispherica. Wesson, Acal., p. 335 (1843). 


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