THAUMANTIAS MELANOPS. 45 
Many specimens of all ages, all preserving the peculiar characters mentioned, occurred 
at Tarbet, in Loch Fyne, in company with Zhaumantias quadrata, during the autumn of 1845. 
We had previously taken it by the tow-net at Oban. 
Plate VIII, fig. 4, aand 4, represent this species magnified, seen in profile and from above; 
4, c, is an ovary; 4, d, the stomach; 4, e, part of the margin and tentacula; 4, J, the bulb 
of one of the tentacles. 
*** Marginal tentacles sixteen and upwards. 
t Umbrella very convex or globose. 
3. Thaumantias maculata, Forbes. 
Plate IX, Fig. 4. 
The umbrella of this very distinct species is globular, smooth, pellucid, and colourless. 
The margin of its rather contracted opening is ornamented with sixteen jet-black ocelli, 
(3 X4-+4), which are alternately larger and smaller, and all very conspicuous, and large in 
proportion to the body. Between each of these is a small colourless tubercle. From each of 
the ocelli springs a colourless tentacle. All the marginal tentacles are similar, and very 
nearly of a size. The sub-umbrella is hemispherical, and divided into four equal segments 
by the gastric vessels. On its lower half, in the course of the vessels, are four ovate repro- 
ductive glands, pale, with yellow or tawny centres. From the centre of the sub-umbrella 
hangs a short but wide campanulate stomach, with four broad, slightly fimbriated lips. 
The four lips correspond in position to the four ovaries, and on the sides near the base of 
the stomach, alternating with the lips, are four patches of black pigment-cells, giving the 
centre of the animal, when seen from above, the appearance of being marked by four 
conspicuous black spots. The black bulbs of the tentacles, when compressed and highly 
magnified, are seen to be coloured by a crescentic series of black pigment-cells, forming the 
ocellus, bounding a tawny space in which there is seen an otolitic capsule. The tentacula 
themselves have a highly annulated appearance. The body measures about a quarter of an 
inch in height. I have met with this curious 7kaumantias in the Zetland Islands only. It 
occurred several times in the Sound of Brassay, but was never plentiful. The jet-black eyes 
and stomachal spots render it a very striking object in the water. 
Plate IX, f. 4, a, represents it rather more than twice the natural size; 4, 6, as seen from 
above; 4, c, the ocellated bulbs; 4, d, the base and portion of a tentacle highly magnified, 
showing the distinction between the ocellus and otolitic capsule in the bulb; 4, e, the stomach, 
with its lips, spots, and the origins of the gastric vessels, seen from above; 4, ,/, one of the 
reproductive glands. 
6. Thaumantias melanops, Forbes. 
Plate X, Fig. 3. 
Another black-eyed beauty, though unarmed with such jetty piercing orbs as the sister 
species last described. Instead of a few conspicuous ocelli, we have here an almost countless 
number, all, however, of extreme minuteness. Argus, the hundred-eyed, must yield to our 
Thaumantias, for it has twice as many. 
The umbrella of the Zhaumantias melanops is sub-orbicular, inflated, very tender, 
