246 PROCEEDINGS OF SOCIETIES. 



of leech, agreeing in all respects with the Monopus medusicola found by- 

 Mr. Gosse on Willsia stellata {vide "Ann. Nat. Hist." for 1855). Two 

 or three of these leeches occurred on each ovary. This was a hardy- 

 species of Thaumantias : five out of seven specimens captured in Belfast 

 docks lived in captivity for a fortnight, having in the meantime borne 

 a journey from that city to Dublin. They were gregarious, great num- 

 bers occurring in the above locality, so that I was thereby enabled to 

 subject several individuals to examination. This Medusa varies from 

 one-third to two-thirds of an inch in length. 



Thaumantias typica, n. s. (miki). Plate XIY., Pig. 4, a. 



The umbrella of this species is very conical, smooth, and exceed- 

 ingly transparent. The sub-umbrella is much more depressed than the 

 umbrella; a marginal vessel and veil surround its opening. The ten- 

 tacles are twenty-four in number (5x4 + 4), very elastic, springing from 

 yellowish bulbs containing an otolitic vesicle, distinctly marked. These 

 tentacles were pilose and granular. The stomach is short and broad, 

 terminating in four fimbriated lips. Radiating vessels, four simple, 

 interrupted by four ovaries, short, leaf-shaped, of a pale yellowish-green 

 tint ; when magnified, exhibiting a cellular structure. I obtained this 

 Medusa on August 21, 1857. Its length was two-thirds of an inch. 



Thaumantias neglecta, n. s. (mihi). Plate XY., Pig. 5, a. 



Umbrella strictly hemispherical, transparent, colourless, and smooth, 

 of rather large size, measuring from a half to one and a half inches in 

 diameter ; sub-umbrella corresponding in shape with umbrella, but rather 

 more depressed, occupying not quite two-thirds of its length. A mar- 

 ginal vessel and veil surround the opening of the umbrella, which is bor- 

 dered by thirty- two (7x4 + 4) very contractile tentaculae. These 

 spring from as many colourless though distinct ocelli. The sub-umbrella 

 is traversed by four radiating vessels. The ovaries are four in number, 

 of a faint blue tinge, and an elongated ovate form. They were very 

 conspicuous when the animal was in motion. Peduncle of a pale-yellow 

 colour, wide at its base, then narrowing, and terminating rather sud- 

 denly in four long, slightly fimbriated lips. 



This Thaumantias resembled T. hemispheriea, differing in the colour 

 of most of its organs, which in that species is pretty constant ; also in 

 the shape of its peduncle and general appearance. The present Medusa 

 is gregarious. I have met with it in considerable numbers on more 

 than one occasion in the same locality (Kingstown Harbour). It is 

 rather a delicate animal. 



Bougainvillea dinema n. 8. {mihi). Plate XY., Pig. 6, a. 



The umbrella of this species is globose, but rather elongated, con- 

 tracted at its opening. In shape it bears some resemblance to the Bou- 

 gainvillea nigritella. Its margin is bordered by four groups of tentacle 

 bulbs, somewhat similar to those in B. Britannica, but the tentacles, in- 



