300 Prof. Mcintosh's Notes from the 



nearly ripe in August. At the beginning of September many 

 had attained 1£ inch in diameter and were mature. 



Forbes described T. pilosella only from Shetland and the 

 south of England ; but it is abundant all along the eastern 

 shores. 



In this species, as in allied forms, it is probable that after 

 discharge of the reproductive elements the Hydromedusae 

 perish ; they certainly disappear from the areas they previously 

 frequented in myriads. 



An undetermined form* was met with at the beginning and 

 end of June, and often in great numbers in July, many 

 having the male elements fully developed, but none had ripe 

 ovaries. They were notable for their size (If inch in dia- 

 meter). This species likewise occurred in the midwater-net 

 in August and once in September. It differs from Thauman- 

 tias jrilosella in the arrangement of the tentacles and the great 

 length of the manubrium, which is proportionally almost as 

 large as in Tima. 



Thaumantias quadrata, Forbes. 



An immature example occurred in the midwater-net in 

 August. Forbes found it abundantly in the harbour of Tar- 

 bet, Loch Fyne, in the autumn of 1845. It would appear to 

 be a late Medusoid. 



Thaumantias octona, Forbes. 



Numerous examples of this small form were captured in 

 the middle of June. It also occurred in the surface-net in 

 August. All were immature. Forbes procured it both at 

 Oban and at Tarbet, Loch Fyne. 



Thaumantias melanojis, Forbes, came somewhat sparingly 

 under notice in May, and, as in the former case, increased in 

 size as the month advanced. It occurred in multitudes in the 

 midwater-net in June, and on an average larger than during 

 the previous month. One, -fa inch in diameter, had fully- 

 developed ova on the 13th of June. It was one of the 

 most conspicuous Hydromedusae in July, when it was fully 

 mature. Some reached f inch in diameter. While appearing 

 almost daily in the midwater-net, it also towards the end of the 

 month was found in the bottom-nets, though the specimens 

 in these were small and immature. It occurred both in the 

 midwater- and bottom-nets in August. 



It is generally distributed along the eastern coast. Forbes 

 procured it in Shetland. 



* Vide Report of the Fishery Board for Scotland, ix. pi. v. figs. (3-9. 



