46 THAUMANTIAS GLOBOSA. 



transparent, and smooth. Around its margin are ranged in close order more than 200 

 fine colourless tentacula, ringed and granulated, when highly magnified. At the base of each 

 is a very small but very black and well-defined ocellus. Round the inner margin of the 

 umbrella is a rather wide veil, which, instead of being borne horizontally in all the specimens 

 I met, was lax and dependent. The sub-umbrella is hemispherical, and divided into four equal 

 portions by the four radiating vessels, which traverse through the greater part of their courses 

 four long, clavate, yellow, rather narrow, reproductive glands. I have represented an 

 appearance presented by one of these glands, as if of a much contorted tube within it. This 

 is probably of the male sex. From the centre of the sub-umbrella hangs the short and 

 very broad stomach, opening by four large, triangular, fimbriated lips. It is usually pale, 

 sometimes slightly tinged with yellow. 



The umbrella of this species was often more than half an inch in breadth, and of the 

 same height. It has hitherto occurred only in the Zetland seas, and is not very common there. 



Plate X, f, 3, a, represents the entire animal magnified ; 3, h, the stomach and lips ; 

 3, c, one of the reproductive glands, and some of the marginal tentacula (contracted), with 

 their oeelli ; 3, d, one of the tentacula magnified when in extension. 



7. Thaumantias glohosa, Forbes. 

 Plate X, Fig. 4. 



Umbrella globular, smooth, transparent, colourless, dehcate. Margin with a rather close- 

 set fringe of tentacula. These are tinted with purphsh-yellow, and when magnified, present 

 a ringed and granulated aspect. They are highly contractile, and very slender. They spring 

 from reniform tubercles of a pale yellow colour, with a crescentic ocellus formed of tawny 

 pigment-cells, inclosing a cavity in which a vibrating mass of otolites is plainly seen. The 

 tentacular bulbs are very large in proportion to the diameter of the tentacles. The sub- 

 umbrella is small as compared with the body ; it is intersected by the four radiating vessels, 

 which traverse in that part of their course nearest the margin four lax, more or less reniform, 

 reproductive glands, firmer and more defined in form, being ovate, in the females. They are 

 pale yellow in the males, tinged with tawny in the females. The gastric vessels present a 

 knob-like enlargement at the point of their union with the marginal vessels. Here and there 

 among the tentacles are little colourless tubercles studding the margin. The number of the 

 former in a large specimen was 7x4-f 4 ; in a small one 3x4-}-4. They evidently increase 

 with age. The stomach is very short, of a pale yellow colour, and bordered by four lanceolate 

 furbelowed lips. The umbrella, in well-grown specimens, measures about half an inch across. 



Tins delicate species is very abundant in the harbours of both sides of the Zetland Isles, 

 usually m company with Thaumantias hemisphcsrica and T. pilosella. It has a remarkable 

 habit of crumphng up, as it were, its tentacula into a confused mass. When very young as 

 represented at fig. 4, c, of plate X, it often extends its tentacles to a great length, and the 

 reproductive glands appear of disproportionate size. Plate X, fig. 4, a and b, represent its adult 

 state, magnified ; 4, d, is the stomach and lips ; 4, e, the reproductive gland of a male ; 4,/, 

 an ovary full of eggs ; 4, ^, a quarter of the margin, with the tentacular bulbs ; 4, h (marked 

 e by mistake m the plate), a tentacle-bulb greatly magnified, showing the ocellus, the ctolitic 

 capsule, and the structure of the tentacle. 



