THAUMANTIAS PILEATA. , 47 



8. Thaumantias convex a, Forbes. 

 Plate XT, Fig. 6. 



Umbrella very convex, but not globose, smooth, transparent, colourless. Margin fringed 

 with twenty (4x4+4) ringed and granulated colourless tentacula, springing from as many 

 tubercles, each pinkish, with a small red ocellus. Between each pair of tentacular bulbs a 

 smaller coloured tubercle, without any tentacle, is placed. The sub-umbrella is large, and very 

 convex. The radiating vessels which divide it, run in the course of four ovate, or rather 

 paddle-shaped, yellow ovaries, placed very near the margin. The stomach is short and 

 narrow, yellow, and terminated by four lanceolate yellow lips, the margins of which are 

 slightly fimbriated. The height of the umbrella is about one fourth of an inch. This 

 Thaumantias is a very common species in the Zetland seas, and among the Hebrides. We 

 have taken it at Oban. It is an active little animal, and very tenacious of life. 



Plate XI, fig. 6, a and b, represent it as seen in profile, and from above ; 6, c, is an 

 ovary and base of a tentacle ; 6, d, part of the margin with tentacula. 



9. Thaumantias gibbosa, Forbes. 

 Plate XI, Fig. 3. 



This curious and very distinct species, which I have hitherto only met with once, has an 

 oblong conical umbrella, not contracted below, smooth, and colourless. The margin bears 

 twenty-eight (6x4+4) pink tentacula, which, in the specimen taken, were habitually borne 

 coiled up. They spring from red ocellated tubercles. The sub-umbrella is very convex ; 

 in the course of the four radiating vessels which intersect it, are as many long, linear, pale 

 rose-coloured ovaries, reaching almost to the margin. From the summit of the sub-umbrella 

 hangs a quadrangular, narrow, rather long stomach, opening by four triangular simple lips. 

 The body is about a quarter of an inch in length. 



Thaumantias gihbosa was taken in the Hebrides. Circumstances at the time prevented 

 such a minute examination of it as so curious a form deserved. It cannot, however, be 

 mistaken for any other species described in this work or elsewhere, and I hope some future 

 observer will seek for and re-examine it. 



Plate XI, f. 3, a, represents the body in profile magnified ; 3, b, as seen from above ; 

 3, c, two of the tentacula ; 3, d, the stomach and mouth. 



tt Umbrella much depressed. 

 10. Thaumantias pileata, Forbes (1841 ). 



Plate XI, Fig. 2. 

 E. Forbes, in Annals of Natural History, April,^ 1841, p. 84, pi. 1, fig. 3. 



Umbrella smooth, transparent, pellucid, shaped like a Chinese hat, being prominent and 

 conical in the centre, depressed and extended at the circumference. Margin bordered by 

 twenty (4X4+4) filiform, colourless tentacles, springing from ocellated bulbs, coloured black 



